Opera plainly states in the release notes that this is an early build of the browser, which means a few features are missing, the most conspicuous being full Flash and Google Gears support. But what what about regular browsing?
With compression on, it's fast. The full NYT homepage, images and all, loaded in
10 7 seconds flat over 3G. Formatting is basically unaffected by the optimization, and the sacrifice in image quality is, while noticeable, not that bad. With compression on, though, the browser is crashy, occasionally poopin' the bed when directed to more complicated sites, like Giz.
There are other issues, like near-total lack of support for nonstandard software keyboards in Windows Mobile, and a broken rotation function. But it's a beta, and so far, so good—if 9.7 turns out as good as it sounds like—and now, looks like—it will, it'll give Skyfire a run for its money and/or debilitating kick in the junk.