BroadbandWatch (BW) done a review of the browser and compared it with the built-in PSP browser with the latest firmware. Here's a quick summary of the points they made.
To test if the DS browser really runs at the theoretical speed of 1Mbps, they used BNR's Speed Tests, the heavy image loading test. After running the test 5 times, the DS came up with an average speed of 156.67Kbps. The speed should be affected by the heavy load on the CPU due to the images.
The browser has SSL support so you can login to shopping sites such as Amazon but, due to the fact that it doesn't retain cookies, you have to re-login to sites everytime you visit them. Popups are also disabled so sites that require those won't work well either.
When BW tried loading their site on both the PSP and DS, the DS actually finished loading the site first so it's not all that slow. However, the PSP does have a certain amount of Flash support, sound, video and a bigger, colourful screen on which you can read fonts more easily.
On the other hand, BW found it's much easier to enter text and browse sites using the DS stylus. Also, thanks to the memory expansion cartridge, the DS loads more sites when compared to a PSP using its built-in memory. When browsing several sites one after another, the DS will run out of memory but this can easily be corrected by resetting the memory and clearing its contents.
In the end, BW liked the easy to browse interface and way of inputting text, saying that users can do some casual browsing without the need to wait for a PC to bootup.
http://bb.watch.impress.co.jp/cda/special/14780.html
