Not only is horizontal scrolling horrible, it also takes about 3-4 seconds to go from result 24 to 25. I often have to do sanity checks for app rankings, and that pagination slow speed is really odd, given that apple mostly caches the first 24 results
To make it worse, delayed horizontal scrolling on my iPhone 4.
I used an iPhone 3G up until the 4S was released. At that point it was pretty unusable. I guess I have one release to go before the same happens to my iPhone 4.
I'm putting it off indefinitely for my iPod 4g, doesn't seem to add anything of use for me. Looks like the Apple way of minimising fragmentation works though!
On the plus side, not having to type a password to install updates for apps is a major win.