A bigger sway bar will increase understeer, but it's not that big of a deal. I run no sway bars at all. It's really a preference kinda thing. No rear will also make you have a bit more grip and make the car transition a bit snappier.
*cough* even if you dont normally run sway bars you should have a set (front and rear) with you at all times depending on track, layout, and conditions *cough*
I downgraded back to a stock one. I havent really had a good chance ti test it but it feels a little grippier.