It is generally considered that the longer a trailer is, the easier it is to back. This is referring to aiming it to where you want it though....and doesn't account for backing into a 90 degree campsite when the guy on the opposing side of the road has left his truck sticking 2 feet out of his site.
It's easy for me to say this not being in your position, but I feel if you have been "getting it done" with a 30' trailer, then you shouldn't have much trouble adjusting to the slightly longer trailer. You should find the difference nearly negligible.
And think about this...how much time do you spend backing up vs camping in it. Just get it backed in as best you can and enjoy that extra living space!
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)