I'm generally happy with the Burstbuckers that Gibson puts in its historic reissues. I've got a few of these things though, so I wanted to experiment around a little, but without really going too far from a PAF style pickup.
I just swapped in a pair of Bare Knuckle Abraxas pickups in my R7, which are working out great. They're hotter than the typical humbucker....and a little less bright on the bridge pickup (which I think is a good thing.) The bottom end seems better, and in general they just seem to have more punch.
For anybody looking for something for their Les Paul that has more punch, is a bit less harsh, and has plenty of output, Abraxas might be worth considering. They're really good in that JTM crunch range, and give plenty of control through the use of the volume pots.
They're a bit pricey, and in the end, they are just a (better in my opinion) variation on the PAF theme...so for those looking for a huge difference, they might not be the right choice.