I think it's between the SIDI TR2.6 Carbons and the Shimano TR-50. The Simano look like they are going to be faster in transition, and breathe better, and are considerably less expensive. Any good recommendations/experiences out there??
I have the shimanos from '06, I don't know if they changed too much. I like them. The only thing is the strap pulls tight towards the cranks. Sometimes if I am putting them on too fast, the straps will start to rub on the cranks. No biggie, just a little weird feeling, usually hardly notice during races, just training. I would go with whichever one fits you better if you have the chance to try both on. I have heard that SIDI's fit in general is very comfortable to a wide range of people.
I understand however that it is preferrable to have the straps open this direction, so that they don't get fouled in your chain/crank in the event they come undone. The SIDI's just don't look like they are going to breathe very well, have one more strap to cope with, and cost $100 more!