Redirect with iRule or HTTP Class profile?

I agree with all of the above responses. In teaching the iRules Optimization courses over the years one of the things we've always said is "If you can use a built in feature, do so." Compiled, built-in functionality will always be higher performance than a script. Even one as highly optimized as an iRule. Beyond just performance there are the issues of supportability, upgrade paths, ease of use, etc. Built-in wins, no matter how easy, fast and reliable iRules are.

Arie makes an excellent point also, however. When the built in features don't offer the exact functionality you want, that is the precise reason that iRules exists as an option. When you're looking to customize things for your environment beyond the capabilities of what is built in, iRules is where it's at.