Viewing angle, in low light conditions:
The 800x480px screen gives good-looking images.
The automatic brightness control generally picks an appropriate brightness. However, in total darkness it doesn't turn the LEDs down in proportion; there must be a lower bound on the lamp brightness.
Need to test in direct sunlight.
To remove the back cover, I needed a paper clip in the release slot, opposite the power button.
You will need the SIM (RUIM) card number if you want to activate international roaming (expensive). To write down the SIM card number, you need to remove the SIM card and turn it over. It is located under the battery: power off the computer (hold down the power button), remove the back, remove the battery. At the south center of the cardholder there is a little tab which must be depressed to release the card. Mine has 3 rows: 7 digits and letters (apparently irrelevant), 10 digits, and 9 digits. The last 19 digits are what you have to communicate to the customer service AI. It's best to get this at the beginning, so you don't have to shut down the phone later to get it.
When you turn the pocket computer on for the first time, it holds your hand as you go through the activation procedure. The main magic (documented several places in the printed material) is to dial *228. (Or *22898 for a prepaid plan, not currently offered for this phone.) But you need some items ready (which they don't tell you in advance).
The user interface and menu system is very kewl: things slide, swing and bounce. I thought I would hate it, but actually it's surprisingly unobtrusive for something aimed at the teenage market. I'm giving it a pass.
The browser is branded as Microsoft Internet Explorer (MSIE), though I doubt there's much commonality with the desktop version.
The DHCP client is much quicker to get an address than Android v1.5 "Cupcake" (old version). My DHCP server is ISC dhcpd, and this machine has no trouble to interact with it.
On the other hand, it doesn't do IPv6, or specifically, it doesn't do RFC-2462 (EUI-64) autoconfiguration.