A lot of these questions can be answered through fourm searches.

To help you briefly, however, the ATTS transmission on the Type SH is similar to an LSD but does its job very differently.

If you will be happy with your Prelude very close to stock (engine-wise) and you like what the ATTS transmission does, buy it. It's a great car. I own one and love it.

On the other hand, if you've got hot-rodding and serious turbo/performance ambitions for your new car, get a Base 5-speed. It will take to performance modifications to the drivetrain much better than the SH.

Both models are fantastic cars. The SH is very, very good but it just isn't always the car for just anyone.