I've been thru them all... Fulldrive, Klon, Zen, KOT, 808, Timmy, etc...
I still have the Fulldrive. Altho IMHO, the new mosfet Fulldrives are brighter than the older pre-mosfet ones, and I recommend the pre-mosfet ones, they are warmer/fatter.
For creamy, the 808 is also hard to beat. Get yourself a Bad Monkey... it's an 808 with 2 tones controls instead of one. Very easy to get thick creamy tones out of it.
I also tried the Pork Loin (twice), the one Joe has been using lately. Not bad at all, very Fulldrive-like, but I prefer the Fulldrive.
Something to keep in mind: they way Joe (and me, for that matter), uses these drives, is to goose an already-overdriving amp, which is MUCH DIFFERENT than using them "as a dirty channel" into a clean or clean-ish amp. When Joe steps on a drive, he's not going from clean to dirty, he's going from dirty to more dirty, compressed, creamy. When used this way, alot of individual characteristics of the different overdrives isn't being used... the drive controls are on the low side... and therefore, alot of ODs will do the same job. For example, using them this way, I was able to get virtually identical tones out of:
FD2
Keeley SD-1
Timmy
Bad Monkey (808 circuit)
Pork Loin
...so close you'd only be able to tell the difference in a studio or a bedroom. THAT close.
I can highly recommend the FD2 above the others simply because is has more tonal options at the flick of a switch:
Vintage mode = standard TS tones (actually, Boss SD-1 is what the circuit is, it's not a TS)
FM mode = less mid-humped version of Vintage mode, for thicker-sounding amps or for more clarity
Comp Cut mode = neck pup heaven. Adds no compression, very little drive, but alot of presence & clarity.