I got a loaner giant AC with a 4 way SPV air on it to ride for a few days.
At first I was annoyed at the low bb, and the fact that it wasn't my chain ring so I shouldn't knock
off too many teeth. But that was the bike, not the shock. The pedals felt strangely decoupled form
the rear wheel when I was standing climbing over big rocks slowly. It's as if the first bit of pedal
energy goes to taking up slack in the shock. That took some getting used to.
If you sit and spin though, this shock kicks ass. Normally I expect some bounce climbing going over
bumps. There is none. That's all there is to it. It's gone. I found myself standing a lot less often
as this shock is so much more efficient when you keep your butt in the saddle. I know this was true
because I was keeping up with the XC racer crowd in our group who usually ditch everyone with bikes
over 22 lbs. FWIW the giant is 31.
The compression stroke feels as plush as oil, and the rebound dampening actually works, which is
more that I can say for Fox air shocks.
I didn't fiddle with it as it wasn't my bike so I can't comment on the adjustability.
Now I gotta see if it fits on my joker :-)
-Bruce.