DISCLAIMER: I am using Linux full time on this laptop. Some people have issues with the fingerprint or trackpad on Windows - theses are software issues which aren't present on Linux.
Fan: they're not loud. It's quieter than my MacBook. In fact, I can't hear it in a quiet room. It's only loud when running full speed; which is rare enough. And that's not louder than the Mac.
Trackpad: it's in.. the regular spot.
Software: it's loaded with Sony stuff mostly. You can remove or reinstall if you dislike it.
Key travel: yes, it's shorter. No I don't see the issue with it, after having used it for quite a long while now. I switch to longer key travel keyboards and back to the Z21 without noticing.
The rest is just "look, my iMac design didn't change in 4 years it's awesome, changing design sucks!".
Now... let's see what the Z21 has and the others.. just plain don't.
SSD: Hello raid0 SATA3 SSDs. Have you ever reached more than 500mbyte/s read/write? Heck, sometimes its going near the 1000mbyte/s sequential. Copying stuff, reading has never been faster. Non-raid0 desktop computer with the fastest SSDs are just way slower. Won't even mention Macs with their subpar SSDs.
Screen: Hello 1920x1080 anti-glare screen. How the hell are others not all anti-glare by default ?
CPU: Hello regular voltage i7 2620M. The air CPU suddenly look.. you know.. just not in the same range.
Heat: what heat? It's extremely well extracted on the side and the rest of the system is at room temperature. Even under extreme load. A problem Apple didn't really solve by the way.
Connectivity: USB? check. USB3? check. VGA out for those conferences? Check. HDMI out /w audio? Check. Audio jack, ethernet, sdcard, lightpeak? check check check check. Tell me when the mac book air doesn't need a bunch of adapters to do more than USB. higher power USB for charging? Heck, check again.
Weight? Lighter than the Macbook air says enough.
Battery life? Extensible well above 10H via a laptop-wide sheet. Smart. Paris-New York, no need to charge. Of course, the standard battery isn't a let down either at ~5H real time use. (they're both rated 7h and 14h max as far as I can remember, but don't quote me on that)
Now with all that, what more could there be? Oh wait.. I mentioned a lightpeak port didn't I.. so yeah, a 600gr+ device can be added to the desk while you're not on the move.. bundling a very decent ATI graphic card, a bluray drive, and more ports. You can drive 4 screens at the same time, although its convenient only up to 3. (oh noes.)
Oh and, does it run linux properly? yep.
So it's an expensive device, but considered all the above, it's pretty decent I guess.
Finally, the actual bad, and yes, there is some bad:
- speaker: they work, but god they're bad. they're terrible. Not a big deal, but still, at this price... the jack is very good tho.
- lightpeak will probably not take off, that said, its mostly used for the side device only and serves as USB port, so who cares.
- way the laptop sits on the desk you may sometimes find positions where its not sitting properly, if your "desk" is not flat