It's funny you bring this up.
I had my 1/48 for a month. The other day I decided to apply stickers (I only applied ones that mattered the most... not all)..
Anyway, I didn't use my originals, either. I used the Kata-toys ones. Man, they're really cool.
They're not as thick and shiney as the cheapo's that it comes with. They stick better (even in rounded places they curl). If you press hard enough they get into the cracks and gel well with the plastic on the toy (not as good as decals, but pretty damn good). They're VERY worth the prices. Besides, just like someone mentioned, it comes with enough to dress up a few valks.
Cutting them out is no big deal. X-acto blades work great and it wasn't as hard as I thought it would be. (of course, this is coming from a non-model builder)...