Buy it if you're willing to put up with the learning curve. No regrets!
Positive Product Points
Once you've put in the time to know your machine, the Professional can't be beat!
Negative Product Points
Relatively steep learning curve.
I've had my Professional for about 4 months now. I bought it used on ebay for just under $400 including shipping. It has taken me quite a while to figure this baby out, but in the last few weeks I've been in espresso nirvana! Balancing roast (I roast my own with a FreshRoast Plus), grind, tamp, and piston pressure takes a lot experimentation, but boy is it worth it! The portafilter is a bit small (I have the earlier version), and this can be a problem for entertaining as it gets too hot, but other than that it is a beautiful work of art, built like a tank, and produces that sweet, sweet nectar that makes life worth living.
Bought on ebay after several email communications and checking feedback of seller to determine he was legit.
Three Month Followup
Well, I wasn't kidding about the steep learning curve, but I'm finally just where I want to be. This baby seems to be far more susceptible to variations in grind, quantity and tamp, but once you get tuned in the shots are other worldly. In addition, I actually look forward to the morming's arm wrestles as I become one with the machine. In addition, I've recently switched to Sweet Maria's Liquid Amber for my home roasted beans which has improved the crema significantly. Although the machine gets hotter than heck, I haven't managed to burn myself ... yet. All in all, I couldn't be happier with my choice.