Well, it's not Wild Bill Davison, for one thing.
And McGriff was another Philly organist who started in the early sixties, well after Jimmy Smith. He always thought of himself as a blues organist, not a jazz organist. Worked a good bit with Junior Parker and recorded with Albert Collins, a good friend, whom he influenced a bit, I think.
I like 'Countdown' but for McGriff recommendations there are several much better ones.
The starting five - Milestone
The dream team - Milestone (Rusty Bryant had died by the time of this one)
Black Pearl - BN
(with Junior Parker) Chicken fried soul - United Artists (done at same session as 'Black Pearl' - Jimmy's organ room in Newark - The Silver Slipper
The main squeeze - Groove Merchant (with Conrad Lester, whom you'll know from all your Freddie Roach albums )
I've got a woman - Sue
One of mine - Sue
MG