It loads very, very quickly, but that's where the good ends unfortunately. It's very jerky, scrolling is horrible, most pages are formatted into where ads are sometimes huge and the text is in narrow columns, links often won't open at all (including here on MacRumors) and you can't zoom in far enough to make links big enough to click on without hitting say page 4 instead of page 5.
I'm sure it'll improve. It can't not! Thankfully it was free.
I just tried it on O2's non 3G network and it's very fast. It's a lot faster than using 3G in Safari or wifi. I loaded a few pages including the homepage of the Guardian and it only took a few seconds before I could zoom in and read the page. It has it's faults, but I can see me using this whenever I'm not in 3G.