They are not really legal for a commercial establishment so you are not likely to find one there. They are good for what they are - as long as you understand that. They are also not a plug n play - they are a hobby - a mostly computer hobby. If you are not comfortable with that then stay clear.As for games -they have almost everything out there -- almost.
They dont feel like a real machine - but I said that already - they are what they are. You can play the games and learn the rules. The shots are not going to react the same as a physical machine. The resale is not as easy either.
I own a couple - but I am a computer guy who likes pinball, so its a perfect fit for me. I can play 300+ different games and still play my 2 physical machines too.
VPCabs & VirtualPin do quite a few shows and hopefully you can get to one to play one first hand.

Good luck..
allknowing2012 on the virutal pin forums.

The things to look for, and put it over the top, is force feedback. Ideally for that price (remember you are talking a total $ sum of PC+monitors+cabinet+other goodies in the price), it should come with solenoids and knockers and perhaps some led/lights for feedback while playing games. They could be added afterwards but its a bit of hassle to tear apart a production VP cabinet.