Lee, even though I own a Scirocco (and still love the styling) I'd say go for the GTI. Scirocco now sitting on quite an old platform and has much less new tech. Plus, the Xenons are way nicer in the new GTI.
Lastly the new LSD is getting rave reviews. So, I think you'll be able to plant nearly all the power through the front wheels with the GTI.
Go on, you know which one to pick

(Still can't believe the insurance on the new GTI PP is more than the R)