I found the lighter the draw the more a poor release shows up, that little extra weight can hide a poor release.
I have a set of 35# limbs and at the bale it makes me work really hard on my release, when I go back to 48# I normally find I'm much more consistent with my overall form. When I have a sloppy release with 48# limbs the miss isn't quite as bad as the 35# limbs.
The higher the Bow weight the bigger the chance of a poor release, the lower the weight the less chance of form mistakes, it's all about balance between control and performance.