I've got no experience with 2speed pump but I'd be thrilled if the highest my gauge ever went was 12! That means you've got very little restriction in your system. When I replumbed our church pool, I added 2 new returns and replaced all the skimmers, feeding new 2" lines. That pump (2hp) has the least restriction of the 4 and flows a steady 140gpm. The other pumps have at least a little bit of 1 1/2" in them and their flow rates are a bit lower. Three of the pumps run at 18-20psi but the 140gpm pump runs at 12psi.

I hope to get a 2speed pump next year for my pool. Enjoy!
Hal