Heavy construction (57 pounds or 26 Kg) with some reputedly commercial-grade components; E61 group head; low maintenance exterior (easy to clean); ability to rapidly make sequential espresso drinks; good steaming. Most importantly: consistently good-to-high quality shots.

The hole for the pressure gauge was imperfectly cut (one can see the outline of the cut a mm or so past the boundary of the gauge). The allen bolt that juts out from the E61 group seems to be 10-degrees misaligned. Both of these imperfections are of no consequence to me ultimately. But for $1059 plus shipping, I would expect better fit and finish. Waiting for 20 minutes for the machine to warm up in the morning can be tough.

I was driven to buy the Grimac Mia by the hassles that I could no longer endure when using my Nemox Junior. The Nemox was leaking regularly and it was just too wimpy for my needs. I gave it away to a friend and I still wince when I think about her continuing difficulties with it. She doesn’t use the Nemox very much now. And the Nemox doesn’t have a three-way valve, thus you can’t back flush it to clean the group head, an absolutely essential feature for me.
I roast my own beans (sourced via the great www.greencoffee.coop folks) in a popcorn popper, and I grind them with a Mazzer Mini (no buyer’s remorse with that purchase—I love that thing). I drink cappuccinos mostly, with some French press occasionally. I use a 58mm Reg Barber tamper with a SS base. I built my own knockbox after being dissatisfied with what was available for a reasonable price. It's ugly but effective, and I hide it in the counter under the sink.
After seeing Chris Tacy’s excellent review at the www.home-barista.com website, I came to see its charm, after first discounting it as too ugly, and besides, I had had my heart set on getting the Bricoletta. But I was concerned about my fifty-year-old house’s ability to handle a machine that drew 20A at a whopping 1900 watts, which is what the Bricoletta is rated at. The Grimac became the primary alternative choice for me. Chris Tacy liked the Mia, but did not like the fact that it was not plumbed and had issues with its steaming wand, saying it was too restricted in its movement and that it has an absurd and pointless bend to it. I have no problems at all with the wand—no contortions required, and steaming is fast and effective, though I see Tacy's point about the silly and unnecessary bend.
My inital order was for the gray plastic-sided Mia but I got the black version instead, since the gray ones were out of stock at EPNW. At first I was worried that the plastic exterior would be phenomenally ugly, in the sense of making the machine look like a giant athletic shoe or a Toyota RAV; besides, my wife wanted an all-stainless steel machine, as did I, but I’ve come to appreciate the Mia’s charm. Why? It is easy to clean. Stainless steel reveals also those spatters, streaks, fingerprints, you name it, that you have to stay on top of every day in order to keep the machine spotlessly clean, or your machine will quickly look like ****. And you have to use some elbow grease in combination with something like JoeGlo to clean it effectively, to get that mirror-like shine. Not so with the Mia. A quick wipe with a damp towel and it’s clean. The Mia has some stainless steel surfaces, but they cover an inconsequential part of the machine that is likely to get blemished. I’ve come to appreciate its low maintenance. After the initial excitement and novelty of getting a new machine, I find that I emphatically prefer easy maintenance to, well, anything else. Nevertheless, the Mia is also much more attractive when seen in person, and everyone who stops by the kitchen always lets out an involuntary 'Wow!' when they see the Mia. Nobody had that reaction to the little Nemox.
The actual espresso-pulling experience is simplicity itself: a massive E61 group head, heavy duty pressure stat, a more than adequate vibratory motor—all these elements combine to produce repeatable shots of high quality and consistency. I would pull perhaps 1 in 20 shots with the Nemox that I would consider enjoyably drinkable. The ratio with the Mia is more like 15 out of 20 shots, and the five I have to dump are always because of me improperly grinding the beans or packing the basket badly. Pulling shots on the Mia is actually simpler than pulling shots on the Nemox. You just turn it on, let it warm up (and wait . . .), do the flush/cooling bit (which requires some on-the-job experience, but no big deal), and press a rocker switch to extract the espresso; press the same switch again to stop the espresso, which automatically redirects the three-way valve. This is even simpler in practice. My wife was afraid that she would take forever to get it right, but she is very happily pulling very nice shots. Making multiple sequential shots is a piece of cake.
Speaking of maintenance, the drip tray is easily capacious enough to absorb a full day’s espresso-making for two people (half a dozen drinks, say), so I only need to empty it once a day. The water reservoir empties fairly fast, what with the need to surf temp the E61 group head, so I am happy that the reservoir is a large 4-liter tank. Back flushing once a week with JoeGlo is routine and easy to do. JoeGlo is great stuff, by the way.
The impression of quality of the Grimac is further reinforced by the heavy portafilter handles (you get two). It does come with one of those ridiculous plastic tampers. Bah, something else for the landfill. I use a La Marzocca basket, rather than the baskets that came with the Mia, but I don't have a real preference either way. Grimac also includes a 'blind' basket to facilitate backflushing. Another aspect I like is the reassuringly heavy rocker switches that resound with a hearty “thwack” when you engage them. Finally, as far as quality is concerned, the machine is heavy, and that’s something I really like about the Mia. Not only is its weight an indication of its structural beefiness, but you can bash on/off the portafilter without budging the machine. Very nice.
Aside from my quibbles with minor quality control-based issues with the machine’s fit and finish, I have to say I really like it overall. At first my wife was not happy about me blowing a grand on this machine, though she too was sick and tired of the limitations of the Nemox. I had first suggested getting a lever machine, like a Pavoni, but she was adamant that she wanted something with an electrical pump, something that wouldn't require too much 'fiddling around'. After a few days with the Mia, she had begrudgingly come around to admitting that it was a worthwhile purchase. Since then, we both consider the Mia purchase to have been money well-spent; we like it even more than when we first got it, which is not something I often experience with consumer gadgetry.
It offers good value for the money—it does its job without protest to very high standards, something you can’t take for granted in an espresso machine. It inspires confidence that it will last a very long time, though of course you need to conduct regular maintenance on any machine that produces high pressure and high temperatures.
I would have bought the rotary pump version of the Brioletta instead if I could have plumbed it in, and if my kitchen could have coped with the Bricoletta's higher current demands. But my kitchen is only nominally wired for 20 amps (the circuit breaker is rated at 20 amps, but the wiring is old and needs replacement—hardly ideal for a machine that would test the circuit's limits), and I couldn't plumb anything in without huge compromises, so I'm happy with my choice: the Grimac Mia is great!

The folks at EPNW are fantastic. The salesperson (forgot his name, dang it) suggested that I ship the Grimac on a pallet via a trucking freight service for about fifty dollars more, as UPS was likely to break the machine. I agreed that it was a good idea.