Have been playing around with FACB tonight, in light of what shinobuXD dug up. I'm only doing handspins because my family are asleep but as these are opposite spin battles where it comes down to stamina/lad etc it doesn't make a big difference.
Basically it seems like a regular albeit very aggressive zombie base/SG - and like most zombie parts, it's probably more useful in general in left spin as right spin opponents are more common. Regular zombies can generally OS defensive zombies if used in opposite spin, too, though this does have comparatively good LAD.
Sadly, the thing I was most hopeful about - using it with the spin stealing upper attacker in the hopes of OSing Circle Survivor combos, didn't work out, it gets force smashed too much. On further attempts against right spin defensive zombies, the AR just isn't good enough - too much recoil, too little spin steal, and also interferes with LAD as it can touch the stadium floor, so AR choice seems to be very important.
Also for whatever reason it didn't work as well using dranzer S's casings - which really shouldn't make a difference, though, but whatever.
Using Wide Survivor and Twin Horn I was able to OS my circle survivor combo, even using my brand new mold 1 wing cross on the latter. Wide defense didn't work as well - got forced smashed too much.
Spiral Change Base has better Life After Death, though I can't tell how the matchup would play out with KO's and weak launching involved without trying it myself, which I can't do atm.
So, it's not too surprising that an aggressive base is OSing defensive zombies when it's a zombie base itself - a significant portion of Zombies can OS Defense combinations used in right spin, though I will say the availability is nice. I still need to check if it's much more practical than Spiral Change Base as while I assume so, I could be wrong.
The KO's on defensive zombies are interesting, but again not really that unique - I need to play around with defensive zombies a bit more I guess, look into the susceptibility to pushouts (it doesn't seem to happen with aggressive AR's - remember that I use my attacker, which is left spin, against defensive zombies on a regular basis) but seeing as I have stated that defensive zombies are among the most reliable types of plastics, I definitely need to look into this before (as I've said, I've encountered it before but not to the extent that it's been anything more than a rare occurrence.)
Sadly though, it doesn't shake the game up as much as I'd hoped (plastics attack, for all of its speed and aggression, can't really do that much to plastics defense, which is part of my lowered interest). Can't use an aggro AR with it, etc. It does seem to be a top tier zombie setup, but so is Spiral Change Base, ie I still need to look into practicality etc. Still, good find, if not quite as significant as I'd hoped.