Aye mate.

RS is just a better car alround.

Better resale, more eye catching, more exclusive. On the subject of power IIRC the head and turbo is also different.

If in a postition to buy both, it HAS to be an RS over a modded ST. How much would you have to spend to match an RS?

If the modded ST has the legs in a straight line, spend a couple of quid and wallop it!