I genuinely love iOS 7 on the iPhone 5, in spite of the ugly icons and less than flattering color palette. So much of it is just so great that I wouldn't want to go back to 6, and it's worked just fine for me so far as well.
But the iPad is a completely different story. I love the new features, I think the lock screen and notification center look great, but the design sensibility of all the stock apps just isn't appealing to me on this larger screen. I really like most of it on the iPhone, but on the the iPad, it just doesn't feel right. Can't quite put my finger on why yet, but I just don't much care for it, which again, is the exact opposite of how I've felt about iOS 7 on the iPhone.
A few more of my thoughts on this matter were posted in another thread, but all in all, while I'm fine with the performance quirks of this beta on the iPad, the overall look and feel of it have me thinking I'll be back on 6 by Wednesday if not sooner. But what worries me is that I know I'm going to want to be using the 7 features eventually with new apps, but if little changes as far as how it all looks, I'm going to be staring at my first major iOS grievance come this fall. There's always been little things, but the design of iOS 7 as it stands right now just doesn't feel right for this device.
Hopefully my opinion magically changes in the next day or so as I use it more, but I instantly loved iOS 7 on the iPhone. I thought I'd love it on the iPad, but right now, I am thinking for the first time that the leather and oddly-used linen backgrounds weren't really that terrible. That's unfortunate.