I ordered one of the HP Touchpads from the firesale, and it arrived!
Here's some observations and initial impressions:
1) Box tries half-assedly to be fancy. They try to make it nice, but didn't polish up the details. Easily seen in that the plastic covering the Touchpad itself is wrinkled badly and looks kinda ugly. Compared to Apple's which always is smooth and clean. The plastic surrounding the cables and power adapter are all slightly scratched.
1.25) At least they included a nice screen cleaning cloth.
1.5) The digitizer quality is definetely worse than the iPad in that you can see the tiny dot pattern on it with just some ambient light.
2) Initial boot and setup took a long time simply because it booted so slowly.
3) Keyboard doesn't make the auto-captialization obvious. At least, I haven't noticed when it's on or off yet. Maybe I just completely missed it.
4) No idea how to open browser links in new windows. It happened once, but not sure how to make it happen again.
(update: after reading the user guide, it's tap and hold to bring up a menu. Half the time, it still sees my tap&hold as a tap)
5) Closing windows is not intuitive. After pondering what the gesture would be I came up with home button to go to miniturized view, and then flick off screen. A 2-step process that doesn't always work because sometimes the window just comes back.
6) Auto-rotation sensitivity is too high. Forced me to find the auto-rotation lock because it was nearly unusable in my hand.
7) It's heavier than the iPad. Glossy back will probably get scratched up badly. Does stick to my hand for a better grip when slightly sweaty.
8) Font rendering is a little odd in the web browser. I saw that some italic text next to plain text had some clipping.