Went to a shop today and played with a mini and a gen 4 iPad. The mini has perfect weight and size! It felt really great in my hand - light, firm grip, easy to hold and use. However... I opened a few tabs, went to Flipboard, switched to Facebook, went back to Safari... and it had to reload the pages. I could also see this "stop" when stuff is loading (just like on my iPad2). Also, things were small on the websites and not really sharp.
Then I played with the iPad4 and wow - what a speed difference. Everything was pretty much instant, I could really tell them apart. Also everything was so crisp! But that thing is heavy... heavier than my iPad2 and that's the only thing I don't like about my iPad2.
So as soon as Apple releases gen 2 mini, I'm gonna be all over it (higher res screen so things are ultra sharp, better internals - more RAM please!!!). The weight, dimensions and how it feels in my hand is already perfect!