The dry grip on the michelins will outshine the rainsports probably but from what I hear not a great deal. But will the rain sports outshine the michelin in the wet? Probably quite a bit (I assume). I can't believe rainsports are the price they are for the reviews they get...
I know what you mean, and I fell for it too. How can you go wrong for that price you're thinking.... They got a little better when the tread wore down but with the thin blocks and soft sidewalls they are terrible laterally. When you feel the weight next to Michelins you realise why they are cheaper.
Dry - Accel and brake, not much in it. Laterally Michelins are much much better and steering feel is hugely improved with it. Whole car feels more responsive and planted.
Wet - Exactly the same as dry (honestly) apart from, I GUESS, aquaplane performance where the tread pattern should clear water better on the rainsports.
I'd like to hear other people reports, especially anyone who's tracked their car.