In my experience, having had a breech babe (DS-#1), then a vertex (DD-#2), breech babies are not more painful to carry. I tend to think it has more to do with the number of pregnancies you are on, because everything with my daughter was more uncomfortable than with my son.
I could have gone on being pregnant with Riley forever, but with Paityn I started having a lot of discomfort around 36 weeks, that continued until it was PAIN at 38 weeks. She was born at 38.5 weeks so luckily I didnt have to deal with it for too long.
So far, with this pregnancy, I feel wonderful (and my baby is head down at the moment)!