If it has to be "flats," okay, listen to what people are saying. If you just want a pretty low profile shoe that doesn't weigh much and will let you go fast, then for everday running I recommend the Brooks T6 or T7. They have a higher heel ratio than true flats, but are still very close to the ground, quite curved to accomodate a wide foot, and very flexible. The fact that you said you want these shoes for everyday training makes me strongly recommend the T6/T7 because unless you're a barefoot or forefoot running savant then you'll probably benefit greatly from the slight amount of heel it has.
(If you buy the shoe, order .5 size up. Don't give up if the sizing isn't right, just have RW send you the next logical size.)
I have the XC2 and the HyperSpeed 4. The XC2 is incredibly narrow compared to the Hyperspeed 4. Here's my problem with that. I can get my foot into an XC2 okay, but it means I have a little bit of extra space and the end of my toes. I don't trip or stub my toes, but it alters slightly the way I run and I just can't tolerate running in it like that. I really wish they'd make the Streak series wide enough to accomodate more than just Kenyans; I love the curve of the shoes, but they're still not wide enough.
The adizero line of shoes are about normal width, but more curved than your average shoe from another company, so the net result is pretty good width. It's too bad they don't sell many of the adizero Pro these days, because that might be a legit option.
I recommend the T6/T7 if you can get it to fit. Otherwise, good luck with what you've heard.