I was planning to upgrade from 7.2 to 7.4 in the near future, just to level up. But after reading your post I am now relatively excited about doing that.
I don't have a huge environment, but I do do have both storage that serves 30 or more hosts, and hosts that are attached to 10 or more storage units with the result that each of my two primary fabrics has ~1600 zones in it.
Peer zoning looks like it would drop that to around 120. I'd end up making one zone for each storage unit port, and assigning the appropriate hosts as peers. The storage end is far less volatile (I install and keep units for 5-6 years versus 2-4 years for hosts recently), so I will be modifying zones regularly, but only adding/subtracting them when storage units come and go.
I like that idea...a lot.