No, no, no, don't go there go to
www.seatcupra.net instead. There is an FAQ on the differences somewhere (do a search as it gets asked a lot).
They are both 6 speed.
210 is an AMK engine, 225 is a BAM, some internal engine differences (AMK rumoured to have stronger rods) and different wheel bearings.
Later 210s have "swoopy" door mirrors, but the 225 has a nicer (IMO) steering wheel (red strip at top). Early 225s came with tracker fitted, dropped on later 225s.
210s only came in flat colours red, yello and black, with some "limited edition" metallic platinum cars. 225s came in flat red, yellow, black and Platinum and Silver metallic were added.
Recaro option on 210 was front and rear, on 225s they are front only.
They both remap to roughly the same.
There are some other small differences.
If you're interested I think there's a herts meet coming up soon-ish.
(now why would i tell you to search, and then tell you the answer anyway???)