I also got one--about six weeks ago. Wow. Just did our first extended portrait session with it outdoors, and we are very, very happy.
Only little concern so far is an occasional busyness of the bokeh, kind of granular, right around f/3.5. Example: shooting a subject about 4' away (45mm face shot), at about a 45 degree angle to suddenly bright sunlight. (It was cloudy all afternoon except for about 3 minutes.
Truthfully, the granular bokeh was not an issue until I cranked up the clarity a little bit in the section of the image I'm talking about. (The model was against a low wall with graffiti, but in the background was a brightly lit grass lawn, which is where the bokeh started to get out of hand.) Using an adjustment brush, going a little negative with clarity and softening focus in LR5 got rid of the problem.
Have used it in bright sun, overcast weather, indoors...Just freakin' love it. Almost afraid to use it for anything but work, but the IQ is so wonderful I can't leave it at home even on fun days.
BTW, I sold my ef 35mm 1.4 L a month after I bought the 24-70mm. So sharp at 2.8 I thought I could put the money towards a nice set of mono-lights, like a pair of Einsteins. When I used LR5's filtering to see how many 35mm shots I took under f/2.2, I realized I would not miss the prime. Plus, in most cases, I'm finding the 24-70mm at 2.8 has as much creamy bokeh as the prime at about 2.0-2.2, for some reason, so I don't regret the sale!
Good luck with yours!