Went from 53/39 to 50/34 and never looked back. I typically cruise (when I'm alone) in the 18-19mph range, and that leaves me around the 4th or 5th gear up from the highest (smallest cog), so there's plenty of room to go higher if I'm with a group or going downhill or have a raging gale at my back. I used to ride a 9-speed where my custom self-assembled cassette started at 13t, and I only spun out on flat ground once, while on a group ride on flat ground where we got a 25+mph tailwind that brewed up on the return leg of a long bike ride, and we were doing well over 30mph and I spun out. Going down steep, long hills I would eventually spin out and just assume the best aero tuck I could and ride it out. Since I'm no racer, the one time I ever spun out in very unusual conditions (I won't usually ride in a 25mph wind), that gearing was totally acceptable, and gave me the finest shifts in the ranges I rode 99.9% of the time. Having the 34t ring up front is really handy for long hill climbs, and with my new 11-speed starting at 11t I have yet to spin out on the 50t ring. Perhaps with a 35mph tailwind in a group ride I could do it, but I'm hoping I never have to find out.
The one theoretical advantage I could see with 52/36t rings is, depending on the speed and cadence you ride at, is that you might be able to stick closer to the center of your rear cassette and get a more optimized chain line for the very marginal gain that might bring. I doubt that's a good enough reason on its own to switch (and to lose out on the benefits of the 34t ring for steep/long climbs). A young, strong racer may disagree. For everyone else I have a hard time imagining any reason why 50/34t isn't pretty much perfect.