B13's are too skinny where my hips are at. It pinches and causes great discomfort. I just put back in my old B14 seats because I could take it no longer.
The human element is ever changing. I am shaped different from everyone on this whole forum (probably) and everyone is different from the next person.
B13 seats have good shoulder, but too skinny for me. I just got back from a drive around and I felt no pinching at all.
On the other hand, I have two, very clean, 91-92 SE-R seats for sale....PM me if you are interested. No holes, rips, tears, or even stains. I cleaned them pretty well before I installed them.