I've got a set of unpotted Mules in my Les Paul Standard. They are very open sounding and have an almost acoustic-like quality to the note. Great for old-school blues and clean tones, but less suited to higher gain stuff. I've found that the potting process smooths out the tone a lot and helps it compress. Great for rock. The unpotted Mules just don't sound smooth enough for higher gain styles. This may depend on your particular guitar though, as mine has a lightweight tailpiece, CTS pots and Hovland MusiCaps which will all play a part in the way it sounds.
I have potted Riff Raffs in my gigging SG and they're great for rock. I think un-potted Riff Raffs would be very spiky sounding with a lot of prescence. That might be the sound you're looking for though so it's not necessarily "wrong". If you have a modern amp, which generally have lots of treble, and you're using high output handling speakers it will be a VERY brash sound.
I'd go for potted pickups in your case.
