96whiteknight wrote in post #16338154
I'm not sure I understand your logic, here.
I love my 24-70L/crop combo, BTW.

OP, you won't be disappointed.
There are some who believe they'll eventually go FF, so they have an aversion to buying EF-S lenses (or 3rd party equivalents). So they automatically rule out the 17-50 and 17-55 lenses altogether, despite these being a more ideal "standard zoom", especially if you're looking for the f/2.8 aperture. And because of that, they're only looking at 24-70, or 24-105, or 28-135, or 3rd party 28-70 versions.
So if the above is true, and already having a 50mm prime in hand, I'd suggest getting a 24-105 as it covers a wider focal length and would be more useful, (despite my feeling that 24mm on a crop is not wide enough). The 50mm prime covers the portrait aspect, and IMO, will provide more pleasing results than the 24-70mm for that purpose.
24-70L original had a lot of variances in sharpness wide open at f/2.8. Some people will tell you, "lenses always sharper closed down slightly," or "what do you expect from shooting wide open?" Well, what would be the purpose of buying a f/2.8 lens if you can't shoot it at f/2.8? Might as well get the f/4. I came across a copy that wasn't sharp (to my pixel-peeping eyes) until f/4.
That said, there are also many copies that are pretty sharp @ f/2.8. So for the OP, I hope he gets a good copy.