Nice derail I started there! There is potential for asymmetrical development from mixed grip. I think it is even in SS, pretty much as vxm wrote it out - i.e. straps are fine if you arent going to compete, or need grip strength that bad.
I personally like pulling them "myself" but Starr in his latest article talks alot about straps, so there is no right/wrong answer it seems.
My Q to Steve was based on my own experience. I had problems with mixed grip due to fucked wrist, and I really let grip strength hold me back. Once I switched to mixed grip, my DL shot up.