I've been beating the crap out of an RRS L-bracket for about 6 years now and haven't felt the need to try any other model as a result. Just keeps on ticking, much like my EM1 Mk2!
I have a Really Right Stuff L-bracket for my OM-5 Mark II because it was the only L-bracket available when I acquired my camera; besides the Really Right Stuff L-bracket for the OM-1, there's also the following: