We've swapped over to SPEC as we feel they're a better solution for an abused drift car, there's nothing wrong with traditional organic/6 puck design clutches we just feel the SPEC do the job better for a car seeing abuse.
Basically Stage 2 is a more durable uprated organic equivalent, Stage 3+ is a more durable 6 puck equivalent.
The stage 3+ is the clutch I use in the chaser, as I killed a 6 puck clutch in one event with the heat generated from clutch kicking etc.
Although the 3+ is a bit more pricey than a max puck, it's a more comprehensive kit with every bearing and an alignment tool.