I own them all, I have real pinball machines, I have the Android versions, the Xbox360, the PS2, and I'm building a Virtual-Pinball machine right now.
Obviously nothing compares to real life, because it's real. It's physical and analog. No HD screen will ever be the same as looking at the world. But with that said, some of the video versions are pretty damn cool. To me the Android/Ios PA isn't much better than the PS2 PA. Maybe clearer with better sound, but almost the same feel. However, I was very impressed with a few VP cabinets I've seen. Not all, but some are fantastic. Which is why I decided to build one. And honestly, with the prices anymore it's become unfeasible to keep buying games at 7k a pop. I like Tron and MM, but I'll never drop 10k on a game. Never ever... NEVER.
As the VP build has progressed, more big collectors keep asking me to build them one next. Mine isn't even done yet, but I have 5 more to build when it's done. One guy already gave me 3 newer Stern cabs (where he got them I have no idea). Which shows me that there is a market for them. Not everyone has the room for 40 machines, nor do they have the funds for them. Some people don't have the technical knowledge to keep one game running, let alone several. So I see a growing market for these machines. I wouldn't be surprised to see them on location in the near future. No maintenance, no waxing, no broken anything, makes sense.
I don't see them replacing genuine machines, but with the recent mega-prices I believe Vpins will have a following if they are well built. Well Built being the operative words.