Pros: quiet, reliable, well built, fuel consumption, easy maintenance, friendly community
I bought a (new) 2001 Vespa ET4 in San Francisco in early 2002. The service I got from the dealer was horrible but I heard the salesman I bought it from was fired shortly after. Vespa Haus in Sacramento has much better service and much nicer people.
The scooter however is awesome. I ride it all the time and I have 3500 miles on it now. The only problems I have had are:
Blue Key broke - Vespa replaced it for free
Bad gas - one time a gas station must have given me some really bad fuel because it didn't want to run for a while after getting gas and had to use octane boost until it the tank was empty. So make sure you always use supreme fuel from somewhere you trust.
Leaking Battery - the only real problem I've had with the scooter itself is the battery started leaking and it screwed up my muffler (appearance only). The guys in Sacramento (Vespa Haus) replaced my muffler and battery at no charge even though it was AFTER my warranty expired!!!
I would definitely recommend getting an ET4 but would say to go to Sacramento or possibly Reno.
By the way I bought the performance SITO Plus exhaust and love it. It gives it a little better pep, better mid-range, and slightly better at reaching max speed on the freeway. It also sounds cool :)