I keep the baffles in and although they're quite a lot quieter the bike still sounds nice, much better than stock. Periodically I decide it's not loud enough and take them out, only to consistently end up putting them back after a few days as although it's great fun with them out it starts to irritate me and the fuelling goes a little fluffy at small throttle openings.
It definitely makes more power up at the top of the revs without the baffles, at the expense of some lower end crispness (as you'd expect) but actually I can do without a mod that encourages me to keep revving out in each gear as I'll end up either having a crash or losing my licence
![Surprised :o](./images/smilies/icon_surprised.gif)