I use the IG Mid and wouldn't say it gives more or less spin then previous versions. I've played with the iPrestige, LM, MG and now IG all Mid's.
For today's game I think you gotta string it low 50's/high 40's and nothing higher, for full poly of course but even hybrid. It's a really quick racket, though I understand why most pros opt for the midplus version. Fresh restrings and new balls every time you go out and hit certainly does help.