I like both...I have 5 RMDs and 3 511s. If I had to choose between the two it would be the RMD, all in all it is almost perfect. If you have larger paws the RMD is probably a better choice....but I have lovers hands not workers hands.. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> So either works for me. The RMD is also just a little thicker through the blade. This can be a plus or minus depending on the intended function.
Andy