I have the Gaggia Factory G106 (1.6L/16-cup) version, which is essentially the same as the La Pavoni Professional. After working with the usual pump machines, I was expecting a bit of intimidation (and pounds of bad, wasted coffee) at first. But it didn't take long between it, my arm, and a Mazzer Mini to produce very consistent (and good) shots.
The machine boils up quickly. The smaller portafilter is a little non-standard (typical for La Pavoni), but I can tamp fine with the short end of a 2" x 2 1/4" tamper you can get from most any kitchen gadget house. Given the portafilter size, I almost never make single basket shots -- typically reserving those for tuning my grind, etc. The double basket isn't exactly a doppio either, of course, but I find the size adequate. And contrary to the instructions for making a double basket shot, I use only a single pull -- a la ristretto -- to make what could be considered a generous, standard single shot. (Disclosure: but I've never met a coffee that's too strong.)
Legend has it that there are those who learn to love the manual, lever shot rather quickly and those who would rather stick with the pump. I learned I fell into the first category -- the absolute "zen-ness" of being more involved with the shot pull really engages you on another level (despite what the mathematically-accurate pump advocates say). This machine makes the lever pull pretty straight-forward and intuitive -- which isn't to say that there's still a good learning curve to get better at it. But challenges are good, otherwise we'd all only be drinking drip.
The big whine about this machine is always the heat. Yes, it generates a lot. This is a great machine if you want to pump out 2-3 quality espressos in short order and be done with it. It's not for lingering in the on state for long mornings, and it's too hands-on to reasonably produce espressos for more than a few people at a time. But within those boundaries, I found the heat an advantage to quick ready times, with the first shots coming out great. Crema every time if your other factors are tuned right. And unlike other machines, I found that this one -- under the above conditions -- can tolerate a bit more "slop" in your espresso-making variables than other machines I've worked with.
It's a sturdy beast of a machine. Yet it's pretty easy to clean and the chrome looks great. Like previous Professional models, there are small areas where the chrome has come off -- but on the whole the integrity is good.
One weird incident, however. I dropped the boiler cap on a wooden floor, and as sturdy as that hunk of schrapnel is, it snapped a release valve closure in it. So just because it feels like a tank doesn't mean you can treat it like one.