IMO, the TF101 with the 4.1 and 4.2 custom ROMs are much faster than any (esp. stock) ICS ROMs.
I have NO desire to get an infinity.
Risks of rooting, well, there are very few risks IMO because so long as you can boot to APX mode (VOL UP and POWER) you can not brick the tablet.
I have also shown a user with a TF101 and a TF700T my tablet on JB. He swears it is faster and smoother than his TF700T, and night and day compared to the TF101.