A great machine for people who want minimal fuss espresso, hot water-based drinks, and a very powerful steaming ability.
Positive Product Points
Steams like a locomotive. Great features like volume-controlled shots, variable volumes, temperature controls that are pretty rigid, and other niceties like an actively heated cup warmer, huge reservoir and more.
Negative Product Points
Crema enhancer filters. I hate them. 2. Preinfusion (normally a bonus) puts too much water in the filter. 3. Built in tamper, while a nice thought, is pretty much useless. 4. The programmed volumes are way off... as in press for a double ristretto, and you get something closer to a triple ristretto in liquid volume. Those Swiss......
Detailed Commentary
The Solis SL-90 is a great espresso machine with lots of brain power. It's in the "automatic class" of espresso machines, meaning once you grind, dose and tamp your coffee, the machine does the rest. It has a computer chip inside that controls a variety of functions, including water volume per programmed shot, temperature variables (Solis claims the machine will brew within 2 degrees of optimum brewing temps - is that Celsius or Farenheit though?) and the machine will not brew until it is up to the right temps.
The steam on this thing is amazing, and the steam knob (THANK YOU Solis for keeping the knob instead of giving us a stupid all or nothing push button steam control) is a "smart" device - it will activate the pump automatically if you're in regular brew mode, or leave the pump off if you're in steam mode. I like that.
Shots from the Solis were uniformely good, if not great. I wouldn't call them exceptional though... for exceptional shots in the home, the only way to achieve them is with non-crema enhanced filters and semi-auto or manual machines. That is, of course, my opinion and may not jive with yours. But the Solis does deliver consistency, and does it in a very easy, nearly foolproof manner.
This machine is capable of producing coffee as well - it can brew up to two 8 ounce cups in one brew session... though I don't care much for the taste of those overextracted drinks. Making Americanos and hot water based drinks is MUCH easier and more convenient with this machine than it is with my other machine - a Rancilio Silvia.
One thing I really don't like about this Solis SL-90 is the crema enhancer filters. Crema enhancers suck. Also, the preinfusion volume is far too much - should be like 1/4 ounce or less, but is, my best guess, about 1 ounce. Maybe this is why the programmed shot times are off by most standards... selecting a double ristretto delivers the equivelant of a triple ristretto. (ie, about 2.5 oz instead of 1.5). You have to play around with all the selectable volumes a bit before you can find the ones you like. Luckily, the machine lets you manually stop a shot at any time.
Overall, the Solis SL-90 is a great machine, built to last, nice to look at, and does it's job very well. This machine is suited for someone who wants more of a hands off approach to espresso and wants power behind their shots and steam. It probably won't enthrall the true tinkerers and experimenters out there, but those folks (myself included) are the minority.
This machine was a gift to me from some happy customers of mine, but it retails for $400 or so.