I shoot Efke R50 almost exclusively in the studio and have been developing it in D-76 1:1. It has excellent reciprocity characteristics for long exposures and I like the grain and tone, especially with metalic objects.
I always use a stop bath and have never had pinhole problems and have never experienced the scratching problems that many have mentioned with these films although I did switch to a hardeng fixer just to play safe.
As far as curling, I haven't experienced any problems that I would consider much beyond normal. This is just my personal experience, there are wide variations between darkrooms and localities ( I understand that it is just a bit hotter and dryer in AZ than it is here in NY ).
As far as availability, remember that this film is now sold under the Adox name so if Efke appears to be unavailable, just get the Adox R50.
Hope this helps.