Been asked hundreds of times. Try searching.
1. Its too loud. even if you don't mind it, other people will, and loud pipes do not save lives. Also, it only makes other riders look bad as we all get filed into the "motorcycles are loud and annoying" category, even if we have baffled bikes.
2. Your losing power most everywhere except for maybe right at the end of your power range (that is, if you actually TUNE your bike for the no headers).
3. Your doing damage to the bike. Not only from running lean if you dont change your jetting, but also from damage as a result of the lack of backpressure.
4. If you can't decide on a pipe, then please, for gods sake, just put SOMETHING on there until you do. Meanwhile, get yourself a sketch pad and think of something. Only YOU have to like it. Or do what anyone who puts function in front of form does, and design a pipe that outperforms everything else. It doesn't matter much how it looks if it outperforms its "pretty" counterpart.
5. IMHO... The bike does not look awesome with headers only. At least, it won't to anyone who knows a thing or two about bikes. Yes, what looks good is opinion. But I bet I'm not the only one when i say this:
A bike with only headers is a bike that is unfinished.
You got a long ways to go goose. We were all total newbs once. the only way to not be is to take peoples advice (not necessarily mine, I'm usually wrong anyway, but believe me I'm right here
) and do a LOT of research.
Heck, i bet just googling "motorcycle exhaust design" will get you a ton of useful information. but meanwhile, pick up some books. may i recommend the following:
http://www.amazon.com/Performance-Tuning-Theory-Practice-Strokes/dp/0854292756
for only 3 bucks... its a fucking golden bible. If your that cheap though, I DO have a PDF copy, but its well worth the download.
ALSO: wrong section.