Your pump or CFC are going to restrict your flow anyway. That being said, it's no reason to restrict it everywhere else.
In my situation, I'm using a little giant pump and a CFC; both are ~1/2"...but I went with 3/4" for all other fittings and 5/8" ID hose in the system because I knew the barbs/hose needed to be larger for a "true" 1/2" ID. I also knew the pump could make up for short runs of restriction with a higher flow rate.
Truth is, you don't need to move high volumes quickly unless you're whirlpooling or transferring. If you're recirculating, it should be a pretty slow rate.
Even if you go with 1/2" barbs QD's that are restricted to 3/8", you'd still be surprised at how much fluid you can move in 5 mins! March pumps can be a PITA sometimes, but once primed, they are more than enough for casual brewing.