I have been experimenting with straps - I'm a petite female and have a 550D.
I bought the black rapide strap for women.(They do a man's version without the curve in it). This is wonderfully comfortable and if I am going to carry my camera ready to shoot for any length of time, this is what I use. The only downside I think, is that you screw it into the tripod mounting - not really a downside until you want to lay the camera down or fit it back in it's bag, when it's a bit cumbersome, or put it on and off a tripod, . One time I accidentally left the strap behind, so this made me think I wanted a wrist strap in addition - just in case.
I've now ended up buying a Matin. This is a neoprene strap - very comfy, but without the curve for the female figure. The plus point for me is that you can make it into a wrist strap as well as a long strap. You attach the two ends to the camera strap connectors as usual, but then there are two clips to detach the main part of the strap. These two clips will then connect together to make a wrist strap. I can leave these attached to the camera all the time as my back up.
The clips seem fine for the 550D but I'm not sure they'd support a 5D or heavier.
I bought the Matin at my local camera shop. There were similar straps for sale, where you could unclip the main part of the strap, but you couldn't then clip the two ends together to make a wrist strap… so if you're shopping for this, check that they will clip together.
Phew! Sorry about the long post!
