Heyyy it's me again! Slow day at work.
When I was in college I too switched birth control brands a few times, but for financial reasons at first (as one brand suddenly became 3X as expensive or whatever). Eventually I noticed a terrible side effect... the pills were making my hair fall out. The last thing I tried was a nuvaring, but it too produced the same effect.
I don't think my libido was affected one way or another, though.
I think, if I were YOU, I would steer clear of ANY hormonal birth control UNLESS you really had no other choice.
Have you considered progesterone-only pills? I think most side effects are caused by the estrogen...