Re: 1., I tried powertop once but was afraid to touch anything :-) what did you do to get 9-10 hrs? I don't think I've gotten far above 7. What kind of usage? (I expect you're not running make -j4 all the time =P)
Also, for those two years, have you tried keeping it between 40-70% charged as they recommend, or have you been more "reckless" about letting it discharge and fully charge?
I turned all the powertop options on. Granted I did do this before I started using it for anything serious as a test case and left it a day. Worked fine.
To get 9-10 hours I used a 9-cell pack and keep the brightness fairly low. The screen kills it more than anything. I also have a 128Gb Crucial M4 SSD in it which is a little less power hungry than most devices. It does only have 4Gb of RAM though.
As for usage, mainly Eclipse with JDT and a Windows 7 VM spun up for Visual Studio 2010. CPU is throttled most of the time and memory usage is about 60-70%. Disk IO is fairly low once everything is up. Unity is running in 2D mode or disabled entirely in favour of Awesome WM. I don't do heavy compile runs as a rule as our dependencies are quite small and coupling free.
Regarding charging, it spends most of its time docked in an Ultrabase but when away or sitting in the garden I rarely have to bother charging it. I've got to the point I don't actually bother dragging a mains charger with me. The 9 cell pack was a year old when purchased with the laptop off ebay - neither were new. The battery had 108 charge cycles when purchased. I have no idea what it has now as I don't know how to extract that info from Linux.
Battery life is better if you install Windows on it as a rule though. I actually much prefer windows on it to Linux but I'm forcing myself to use Linux as my primary OS for a few months to see how I get on.
Windows 8 will probably give best battery life as it is tickless as well but I can't stand metro.
1. Fine. 9-10 hours with a 2 year old 9 cell battery. I run powertop and don't use unity though which is a power hog.
2. Everything works flawlessly
3. Yes but you have to enable it as Ubuntu turn hibernate off by default.
4. External display works fine. Never tried rotation.
5. Yes.
6. I don't use it. I use the nipple mouse. all trackpads make my fingers hurt as I have skin sensitivity issues.
7. Several orders or magnitude better than a MacBook. Keyboard is amazing.