Any advantages to these in any kind of performance besides just being light weight? Am wondering if it can help even more to keep water cool to maybe ward off detonation in heads. Thanks.

Yes, the aluminum intake is much lighter, but it also flows better. The increase in flow isn't due to the material used, but the design. Prime example is the Edelbrock Performer. My engine seems to make more power with the Performer from ~4500 rpm+. If they made the same intake in cast iron it would perform just as well.

I don't think you'll see a difference in detonation between an aluminum intake and a similar cast iron one. If however, the higher performance intake allows better breathing, with the increased manifold filling you may see an increased propensity to detonate. I've seen that on the dyno.

Mike