Medusa 2S or 3S for CRT.5?

[GO-RIDE.com]

Hey All,

I now have two e-crt.5s.

CRT.5 #1 - is my wife's that is built with a stock ofna chassis and buggy wheels, and run it with a Mamba Side Winder and 4600 motor. I kept it as light as possible and don't have heat issues running on 2S maxamps 4200 batts.

CRT.5 #2 - is my original crt.5 with a RCM chassis, my Revo shock upgrade, truck wheels and Novak GTB/6.5 system. It has a lot of aluminum upgrades and is a lot heavier than the other. I run it on 4800 or 5000 hardpack 2S batts.

My beefed up crt.5 is ready for more motor to go with it's mini-monster look. I'm trying to decide between a (Medusa 50mm 5900kv on 2S) or a (Medusa 50mm 3300kv on 3S).

5900 on 2S (95amp cont, 115amp peak)
Pro - would be better because I could share lipos with my 10th scale race vehicles
Con - Will probably run hotter and be harder on batts due to the higher amp draw

3300 on 3S (75amp cont, 90amp peak)
Pro - probably run cooler and be easier on batts plus may have more punch
Cons - have to buy 2 new batts just for this setup

What do you think?