Brewing and steaming performance. The unit gives a very solid feel, seems to have been very thoughtfully designed compared to my late Krups.
Negative Product Points
As others have mentioned, the steam valve has a tendency to leak a little sometimes. My machine sputters and leaks a small ammount when warming up. No big problem at all though, I don't get any local flooding. :)
I paid 3950 SEK here in Sweden (divide by approx. 9), which is hideously expensive according to friends and family who haven't been hooked yet. However, I have to say it is a very sound investment if you're serious about your espresso.
I made the mistake earlier in my barista career of buying a Krups Novo 4200 (the semi-auto "digital" one with a row of diod lights). It brewed a half-decent espresso and produced steam although it took quite a while to get enough for a Latte. In comparison the Krups seems like a toy compared to the Gaggia.
All in all, a excellent home machine with the apperance and (almost) the performance of a commercial unit.