Spin penalty isn't severe enough. It's a big problem at scrambling as well. Chips and pitches and flops back up way too much/fast. Makes getting up and down way easier than it should be. Scrambling stats in the tournaments show this.
I agree with Flops appearing to have more bite than they would on Tour.
But, if you Flop on Tour Pro level, at stimp 14, with anything other than a 64 degree wedge... the ball will roll out.
So, some of it is just that Tour players are choosing to hit Flop shots from arguably worse situations; with the green sloping away, short-sided, using wedges with less loft.
As far as spin out of the rough, for approaches... it seems to depend on how far away from the green you are.
So, longer clubs don't tend to bite out of the rough. But, wedges are able to bite, just like they do in real golf.
Certain shots that have been hit out of the rough simply cannot be duplicated in this game. Like the Y.E. Yang approach in the 2014 PGA Championship, on the 72nd hole.
I don't think they can add any more penalty out of the rough, and have it play any more realistically. It's already really tricky to find clubs to hit with over 20% rough penalties, because the penalty keeps increasing, until you have way too much club, anyway.