EDIT - perhaps : http://www.phoronix.com/scan.php?page=news_item&px=X1-Carbon...
But apart from that, yep, I'm quite happy with my setup.
btw, is there a comparative study anywhere about how long the battery will last for a MB running windows (in parallels or botted) vs MB running latest apple OS?
I don't use boot camp very often, but when I do the battery gets drained faster and the laptop gets hot to the point where you have to be careful not to touch the space between some keys.
Parallels/VirtualBox/etc runs fine, but makes running anything with a GUI extremely slow. In some cases it doesn't matter, but in others...
"Parallels/VirtualBox/etc runs fine" when you do that, is the battery of the MB running down faster? or no big difference?
how much memory do you have on your MB? and how much do you allocate to the Windows VM instance before you start it? did you try to allocate more memory and see if the performance of those windows app with GUI, which you say is very slow, getting any better?
When running VirtualBox I see no big difference on battery drain, at least nothing that can't be attributed to extra workload.
I think that the last version of Parallels I used was 6, so I can't really talk about it, but again, my experience at the time was the same, the battery lasted more or less the same.
A link that someone else posted blamed the crappy windows drivers by Apple and it does make sense.
As for your other questions, I have 16GB of RAM, I've used windows 7 and 8 VMs with 2, 4 and 8GB in this laptop.
Now, you have to take into account that I don't usually use windows VMs as normal machines, I usually fire it up, do whatever I need to do and shut it down. Once said that, giving it more ram helped to some extent, but not much. For example, the difference from 2 to 4 was much more noticeable than from 4 to 8. I haven't tried with more memory and ended up leaving it at 4GB.
I kind of feel the need to point that I'm talking from memory with nothing like hard evidence or tests, so don't take this as an fact or anything like it :)
The most recent example I can think of was Inkscape. I suddenly needed to edit a svg, couldn't install Inkscape on OSX (I had a problem with XQuartz, a requirement) and the only suitable VM I had at hand was windows 7.
After firing it up and installing Inkscape there, I found that redrawing the screen took 10-15 seconds, every time I moved the svg around. After trying to work on it for a few minutes I found it so exasperating that I prefered to go back, fix the issue with XQuartz and use Inkscape in OSX.
I used to be a dyed in the wool fan of Lenovo running linux, but due to some need to work on iOs development I finally bit the bullet and switched to a Macbook Pro. I maxed the specs on it and I have had no problems at all. It fulfils all of the requirements the OP has, and honestly stays pretty cool. I honestly don't believe I will be moving away from the MBP any time soon.
-MuhPirat