I had a '76 SG 1500 which is similar to the SG 2000 except the it doesnt have nice inlays & binding, and coil-tap options on the pups. I swapped out the original pups for Mules as soon as I could and they stayed in the guitar for about 8 months. But it just wasnt right.
I then put the originals back in and WHAM! The guitar came back to life. As much as I respect BKP (been through a few sets of BKP pups) and other pup manufacturers, IMHO, a lot has to be said for the expression "If it aint broke, don't fix it".
Personally, the pups in the SG1500 I had were really, really good and that guitar absolutely rocked. Bloody heavy mind, and the first thing I did was invest in decent strap locks...