Depends. If .591 is running well for you, then probably not. If you're having troubles with .591, then I would. Ultimately though, you probably won't notice much of a difference between the two of them (again, unless you're having troubles with .591)
I don't know why you have a leak. I had a big leak before going to .607 (was on .537), but I don't have the big leak now. I run a custom theme that I love and 20+ apps. I use all the apps you listed.
I boot up with about 10 more MBs (37) and it doesn't drop too far.
i have to agree with k8108 the last few hybrid that i have been use i have had bad leaking but since installing .607 i boot up @ around 40mb.
I have the berry stone theme, LifeChurch.tv, about 1gig of Docs to go, Meterberry Nfl Moblie, Pandora which i use around three to five hours a day, BB Maps, BBM, and two games.
Where with running .548 hybrid ( I know running behind) i would boot up with around 33 - 35mb with having to do a reset at least once may be twice a day, where i have been running .607 for two days and have not fell below 39mb with only my daily reset with some heavy use. But wheither or not to switch from .591 i cannot say but from.548 to .607 there is a world of diff. just my 2 cents
