I will answer first. I have had 2 comps for my 1911 one of them a cheap $19 off of e-bay, and one about $50 from brownells. I have since resold them on e-bay.
I never noticed much difference between the two. I didn't have them fit to the barrel or anything so that may be why I saw no real performace increases (i was pretty new to my hangun also and just wanted to try them cuz i thought they looked cool.)
be willing to refinish your pistol if you find a comp you like because more than likely it will not match and stand out like a sore thumb on your pistol.