I started carrying the XDm 9 compact 3.8 and love it but the SR9c is more for me. When I brought the SR9c at the range, I had the safety on a few times which caused me time delays in racking and firing. I also noticed that I never put the safety on after shooting. Shifting systems can cause some problems (as stated) so if you're used to 1911 platform, this would be perfect for you. It is quite easy to get that muscle memory back so 2 range trips and it's all good for me.
The trigger on my SR9c is scary light. Too light for carry. I would never carry it with the safety off. I wish Ruger would make a compact traditional DA/SA pistol.
I carry my SR40c with the safety on with one in the chamber. When carrying my LC9 I don't use the safety. Mainly because the LC9 has a much longer and heavier trigger pull.