I see the 24-70 f/2.8L II lens a different way than I normally do regarding zooms vs. primes. I don't shoot wider than f/2.8 on FF typically, so the added cost of the zoom was well worth it. It beats any of Canon's primes in the 24-70 range, at f/2.8 and narrower. I sold my 24L, 35L, and 50L when I got that lens, because the IQ was certainly better than yes, even those primes.
I don't recommend a 24-70 zoom lens, however, on a crop body (APS-C). FF though, yes, for once, you really do get all of your $2299 worth.