I dont see much wrong with a turbo spooling full boost around 4k on a stock bottom end as its much easier on the connecting rods than one which making mounds of torque at a really low RPM (pre-3k). That is obviously more fun, but less advisable for a stock blocker for longevity.
The STS may not be able to make 600+, but its not quite as rough on your con rods with the high RPM spool either.