The install times on the demos do suck. Given that the Wii and 360 manage to avoid them, I'm not sure why Sony decided to go down that route with the PS3.
If I had to pick a few additional gripes:
1. No HDMI-CEC. I agree, not many people use it, but it would actually have been nice with my current setup, and Sony is supposed to be supporting it.
2. No SACD over HDMI, and no DVD-A support at all. The latter is understandable given Sony's corporate leanings, but the former is incomprehensible.
3. No proper IR support built in. Sure, I can spend $20-$60 to put it in, but a built-in IR port would have cost them 50 cents.
4. No stereo A2DP support for stereo headsets - they don't work at all. Don't tell me it's there - it's not. Google around before you tell me I'm wrong - just having BT-2.0 hardware doesn't mean you have driver/firmware support.
5. No hardware upscaling of PS3 games to 1080p, forcing you to rely on your TV's scaler. The 360 got this very, very right.
6. HDCP required for games over HDMI. Again, yes, it's true, don't "correct" me with "how it should be".
7. No bitstreaming for DTS-HD, DD+, or TrueHD. Don't tell me I don't need it - it's an option I would like to have, in case my receiver decodes better than my PS3. Clearly, Sony thinks it's something useful, as their new 820 and 920 receivers do support bitstreaming those formats into them.