ST's are very very good cars, I drove my mates last night ( is even orange! ), and it has to be said its a fantastic car but would I swap my small turbo STD escos for it? NO WAY...
1) escos's are the pinnacle of the RS era, there will never be another like it I fear
2) escos will never loose value like an ST, will still be worth very near what you paid for it in 5/10 years time if kept nicley
3) 4x4 vs FWD- nuff said

I know that a new car has all the benefits of warrenty, peace of mind, no rattles/bumps etc, but thats all part of the RS experience

keep your escos