Default [Q] 3G internet slowed down

Hey guys,
I'd like some advice on a matter.
I've been using GPCR rom for a while now, with battery drain - but that is not the main problem.
The issue I've been facing recently is that my 3G internet is slower that ever!
It's much slower than it should be, and I'm not sure if it's problem with baseband or rom...
I've considered several options:
1. Stock gb
2. GB rom (e.g. Small Korean, Thiaiz,etc)
3. Stick with GPCR
I'm not sure what to do. I've got exams now so I can't fiddle much with the device much, but
I'd like your honest opinions so I know what to do.
Btw I'm using GPCR v2.7b (but problem was same on v2.1 as well) with v28b rooted baseband.
Thanks in advance!
SD

P.S. What's the best battery rom for GB?