Worth switching from 32bit to 64bit Windows 7?

[Xiph]

Intel Core 2 Duo T7300 @2Ghz (not the mobile one)
2 Gb Ram
Geforce 8700M GT

I'm currently running Windows 7 32bit and was wondering how much of a performance increase I would get from switching to 62bit?

Reinstalling everything in 64bit flavors, mainly PS3 media server that has to be compiled to work, is a pain. I'm trying to make my mind up and was curious if anyone knew how much of a change I could expect to see if any.

Right now I'm limited to overclocking my entire system through setfsb and can only get a 10-15% performance increase that way

I'm trying to get zelda twilight princess from 15-20fps to 25-30fps

[Xiph]

Went ahead and did it, gained 0-2fps in opengl and 5-7in direct3D in Zelda: Twilight Princess

[Gundark]

Actually, if you use JIT, x64 is slightly faster, but in JITIL it is the other way arround. In generaly, i have Vista x64, and best results i have (in case of Zelda TP) is x86 JITIL. However, i am usin Dolphin r4995. Didn't tried latest revisions. Maybe they have changed things.
Other than that, i prefer x64 from other reasons.