Do I really need bigger rear sway bar?

My setup:
-Ground Control coilovers spring rate:500frt:150bck with Strano HD bilstein shocks: revalved fronts: stock back
-ST 35mm front sway bar
-Double Adjustable PHB
-BMR LCA
-3 point STB
- Welded SFC

Do I really need bigger rear sway bar (right now I have stock). My car is 100% street setup. I was wondering how much improvement rear sway bar will give me. I was thinking about 1LE 21mm or 23mm, nothing bigger than that...
Sebastian
Thanks

It will help loosen up the rear if you feel that's needed. Your call.

The 21 mm bar is something that is complimented by a T2R and R compound tires. If you don't have at least the T2R and it is a street car, then I would hold off on running a bigger rear bar.