I've got this turbo (ball bearing, .63a/r, 3200 vigilante multidisc) It spools pretty quick even going through a dutt. neck stock intercooler (getting ready to put a big stock location on). I can build 3-4#'s boost on the street with factory tires. On the track with a good tire I'm sure it would build at least 10#s on the foot brake. I think it would spool up even better with a bigger intercooler. It's not going to spool quite as quick as a 44, but with the right setup it really isn't an issue, and on street tires it would be hard to hook if you boost launch a 66 anyway. I don't see why anyone would have tuning issues with this turbo
I got a turbo tweak chip and razors alky injection and running 22#s boost with virtually no adjustments needed at all to the alcohol kit or the chip.