We've been taking advantage of these from the day they went beta. It's a shame they're finally switching on the full price, we had quite a savings in the interim (they had been priced at the same level as "1X" dynos during the beta period, the last few months).

Our apps (Rails) tend not to be incredibly hogging, so we've been running 8-9 Unicorn workers per dyno, depending on the app, up from 4, and it's worked fantastically. With one app, we were able to scale down from 12 to 6 dynos, which helps with the routing mesh "issue" that begins to really present itself with that many dynos.

Per aculver's post, I'll have to take a look at Adept Scale - it sounds killer.