I've already done 2U IPT, next year I'm doing:
4u English
3u Maths
Physics
Economics
My ext1 maths definitely isnt going to count (but i need an understanding of it for my desired uni degree), and probably my worst 2u of English wont either (or, if I happen to do well in them all, 2u of my other subjects).
I was considering keeping Software Design (coming 1st in it, I'm going to look like an idiot for dropping it), and not doing 4U English, until I found out I wouldn't have any free periods ever, which given 2 years I had to do EXTRA periods, let alone have frees, that prospect is like, 5 years of aspirations made possible.