I found Pinball FX2 a short time ago and played it a little bit. Physics are really nice, especially the ball movement looks very realistic. But the slingshots are all way too weak - this is totally unrealistic. I know no pinball machine with slingshots THAT weak!
As I'm also a cab user I really want to see that the DMD could be placed on another monitor (in my case 3rd). As most cab users have the DMD-monitor mounted in different ways I would recommend a freely moveable DMD to place it on the right position.
And it would be cool to have a backglass for each table. Same as above, same as on a real cabinet.
Freely selectable keys for control would be also very nice.
All other things seem to be ok for now - but maybe I'll find something more to say in future...
