I ALWAYS stay away from LB posters. To me, a folded poster is WAY more valuable than a linenbacked poster.
Main reason: you never know what kind of work has been done to your poster. A good restorer can hide a lot of stuff. I was burned early on and I never came back. I will always look for a clean folded copy and will pass on 99% of LB posters. If I know I will not be able to find a good folded copy, I will buy a shitty one before I buy a LB copy. LB is last resort. If my folded copy is bad, I will have it linenbacked myself. At least I know what's up.
I will only buy a LB copy if it is the ONLY one I can find.
Also, storage is a big element. I own almost 12,000 movie posters, and LB posters take a lot of room.
T