Agree on the Lucky Labs durability. They don't seem to last as long. Yes, their cutouts are also not only more accurate but they are pre-cut. No need to try to poke out little pieces of the wrap to make room for buttons and such. Their service is infinitely better too.
Slick Wraps offers more stuff with a lot of it being novelty (glow in the dark and such). Their customer service is pretty bad. Also, on some of their thicker wraps (the glow in the dark one specifically) they use a weird metallic backed vinyl that actually degraded my signal on my iPhone 4 (ATT version).
I prefer Lucky Labs mainly for their customer service. Yes they are lacking in variety of products compared to other skin services, but if you have an issue they get it taken care of. Even if you apply one wrong or a strip is ruined out of the packaging due to humidity, they do replace it with zero questions asked. Awesome company.