Why is my HTC Incredible's WiFi so slow?
OK, this is embarrassing but I'll leave it here for posterity anyway.

Tried another network and got slightly better performance (probably b/c the hotspot had weak signal strength).

After more investigation I realized that it was connecting to my network then disconnecting. Turns out the password was wrong, but rather than actually telling me that, it just connected and then a few seconds later (after I'd left that screen) it disconnects.