I know, I am in the same boat you are with the rear! I weigh 145 w/o gear, Jeff recommends the 5.0 rear and staying with the stock .35 front springs. So, I ordered the 5.0 rear, should get it tomorrow, the shock is off and getting serviced right now, so I am hoping to have it back together by Friday. Test run it over the weekend. I am alittle worried about it feeling "mushy", but am thinking it will be better balanced.
I ride a lot of single track, which the bike handles great in. My problem is higher speed, more open stuff, I don't feel comfortable hitting any water breaks, the bike(suspension) just doesn't handle a jump well at higher speeds, not motocross jump, the small fun little water break jumps.
Does that make any sense? I don't really know how to describe how it feels.
Oh well, good luck!
I have read that if you are not happy with the spring rate you get from Jeff, he will exchange them for you, probably just the cost of shipping.