Pro's and con's of detailer/buffer?

If you mean a rotary buffer, you need to be really careful unless you're very experienced, or you could easily ruin your paint.

For non-pros, a random-orbit is the way to go, and most prefer a Porter Cable:
porter cable 7424 - Google Product Search

I've never bothered to get any power detailing tools, and I've always been pretty serious about keeping my cars looking great.

 

For most polymer applications (and polymers are by far the most common "wax" used these days), a power applicator or buffer is not needed at all.

I have a very nice Porter Cable random buffer and have used it once in about four years I have "waxed" my car about once a month. Clean, US made 100% cotton towels are far easier and better, in my opinion. US made because then the labeling can be trusted and the cotton is really cotton without synthetics that can sometimes scratch your finish.