I went back to iOS 6.1.4 as well since I didn't want to be using buggy stuff long (just installed iOS 7 to play around with a few days and get a feel for it).
My observations: iOS 7 was cool to use for a while but exhausting. I don't care about the bugs/performance since its a beta and I know those will be resolved when it finally comes out.
The exhausting part is the interface. While at first it was nice to get a breath of fresh air, I just feel like the interface is more chaotic. For example, by removing a lot of lines and dividers, things just seem to blend in together.
Case in point: The Mail app. It no longer has divider lines between mailboxes, they are all just written on one block of white. And with little contrast between that area and the light grey areas on top or bottom the whole app just looks like chaos. Same with music app, same with many other apps.
I think they really need an accent color.
It reminds me of the time I painted a room completely green. It looked okay but "unfinished" So what I did was I painted a 10 inch purple line across the center of each wall (horizontal line), as if to split the wall in two green halves. All of a sudden the room looked attractive and complete and wayyy better than before -- all thanks to a simple, but bold purple line.
What iOS 7 badly needs is some accent colors also. White and Grey go together, sure, but there's no contrast. They need to accent each app with a bold contrast color, and add some contrast to some of the elements.
They can also accent the elements a bit, so that your eyes know which parts of the screen "go together" and help guide your eyes.
They don't have to make fake 3D effects or heaven forbid skeuomorphism. They just need to add some colored lines, or fill a few spaces with solid colors. It will look 10000x better. And complete.
Also, they need to remove the b.s. textures from places. If you go flat design it should be flat with SOLID colors.
Oh, and the lock screen should still tell you which way to slide. If you are a newbie you may think sliding up is the way to go because there's an up arrow.
I hope that they make a lot of visual tweaks by the time they launch. I know the odds are not in this favor as typically I hear betas were visually complete just had to have bugs ironed out or back end features put in, but I hope this one bucks the trend.
If it doesn't, I think this may be the first release of iOS that many people skip. I for one may skip it and just upgrade to iOS 8 when I know they will address these problems (or else Apple is going to be in serious trouble) or just wait entirely until I get new hardware. If this happens, it is going to damage Apple's fragmentation argument.
As much as I enjoyed the cool animations and iTunes Radio and such, I am back on iOS 6 and feel much better about it.