For me, 8.1's improvements and advantages exceeded its drawbacks compared to 7.1 as of firmware 2.52.22. The AP1 improvements in that version really made AP1 into a mature, reliable driver's aid, and it's worth dealing with a few of 8.1's idiosyncrasies e.g. hiding icons, difficult-to-navigate media player, and a few other UI annoyances.
If you had asked me this for the 8.0 and early 8.1 releases then I would have considered going back to 7.1, but as of now, I would stay with 8.1.
Note: I have an 85D, therefore I'm unaffected by the P90D counters issue in 8.0/8.1. Those would warrant severe consideration in answering this question if they applied to me.