Spec Stage 2 Clutch. Which flywheel?

I've got a Vortech chargecooled 05 with the 462bhp and 417lb ft torque and so am going with the Specs stage 2 clutch. However, you have to have a SPECS flywheel and you have the option of a steel one of an aluminium one with a steel replacable insert. It's about $100 difference so which do you think is the best option?

It's OK, I got a swift reply from SPECS. For anyone interested, the Stage 1 holds 410lb ft of torque and the Stage 2 520. I asked about the benefit of a Stage 2 Plus and which flywheel to use.

"The st2 has a slightly sportier engagement (but still street friendly) and will hold more power. The st2 feels very much like stock, which a lot of customers like. If you decide to use slicks you might like the st2+ better (real slicks, not drag radials).
The flywheel of choice would be determined by what rear end gear you end up with. With stock gearing, go with the rebuildable billet steel wheel. It
is lighter than stock but not as light as the aluminum. If you are running
anything above a 3.73, then the aluminum would be the choice"

Hope this helps anyone searching on this question.