I'm with Malenko and Chad. I have real pins. I have played a couple of virtual pin cabs. I've played VP and AB'd with games I actually have. I played an ultrapin at Disney quest and it was lame.
THEY are DIFFERENT. One doesn't destroy the value of the other. I would buy one real pin before I bought one nice virtual pin with 100 tables for the same money, but that doesn't mean the simulator can't have redeeming value and provide a lot of fun and some valuable rules learning. You will not become a skilled, nuanced player of real pins with one because of the differences. I've played vpin versions of games I hadn't seen IRL prior to tournaments and feel it helped me learn strategy/rules.
The issues with physics and flat appearance get better constantly at a slow rate. the stuff like the head tracking 3D and animated backglasses may take it past the physical at some point even.
The other BIG difference is I could build one. This is the only reason I have an arcade game. I would never be motivated to buy a cab commercially. It's doable to re-theme or re-rule an existing pin but building one from scratch, the value really isnt' there I feel on a hobbyist level. As in by the time you got done with something decently spec'd and built, P-roc, etc, you could have bought two new sterns and it might still suck, because face it, you're not Steve Ritchie or Pat Lawlor.
Even though I would choose the real, I could see myself building a nice vpin (or a sleeper rat rod one in a blown out real pin cabinet) because I like building this stuff and they're fun projects. more to them than a mame cab. The last project I built wasn't a machine I wanted to keep long term either, but someone wanted it and it was damn fun to put together and run for a few weeks.