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probably the sram, ettix qs have had loads of trouble with the fsa rings shifting badly with di2 this season (how much of that is real or just riders jumping on a bandwagon I don't know, but presume the former) for that reason I'd go with sram
I'd honestly look into a praxis conversion bb though, I've not heard any creaking stories with them and the idea seems solid, and the front shifting will drastically be improved, if not maybe have a look into the turn zayante cranks? stiffest around and will have the next best shifting to Dura Ace rings with shimano, thanks to the praxis rings
this is food for thought:
https://fairwheelbikes.com/c/reviews-and-testing/road-bike-crank-testing/
it'll be more universal should you change frames, but the sram red does very well in stiffness to weight for the price and the shifting is probably going to be worse with either the sram or fsa when using shimano