I'm in basically the same boat. I have experienced some issues, but none of the ones he mentions. Further, in my experience anyway, this has been the smoothest major OS version upgrade I've experienced. Obviously that won't be true for everyone, but it is for myself.
"You don't feel like Mission control is a pretty big step backwards from even the old spaces UI (on a single monitor, it is)?"
I don't personally, but to each his own. I think it is refreshing that they cleaned things up and consolidated what was once multiple disparate UIs (dashboard, expose, and spaces) into a single UI. Formerly, I didn't even try to explain to my wife how to use Spaces because it was just too confusing for her. Now that it's all basically one UI, it is easier to explain and requires no manual configuration. I am a bit annoyed at some minor quirks, like the inability to manually rearrange desktops, but I don't consider it a step back.
"You think Launchpad is not pointless?"
I just simply don't get this complaint. They added a new feature. If you think it's pointless, ignore it, but what is the point of complaining about a new thing which you are not forced to use which does not deprecate any old feature?
Anyway, everyone is certainly welcome to have their complaints, especially someone who has experienced some poor issues, but I agree with the grandparent comment that often someone's configs can get mangled and they can lash out at, in this case, Apple, as though it is entirely their fault. I would be extremely surprised if all of these complaints were entirely valid and the writer of the article were not tinkering with their system intensely to have all these issues pop up.
Maybe old configurations don't mess things up. I had nothing but great experiences with Migration Assistant and upgrades since I started using Macs in 2005 until Lion, even through the PPC-Intel transition. I had a problem with my upgraded Lion machine though, it no longer connected to my Windows 7 machine's SMB shared volume. After doing a fresh install I was able to connect again and I had tried connecting from 10.6 so I know Lion was at fault. That's the only issue I had but it does lend some credibility to the fact that old configurations can be problematic, in my eyes.
I've never had a kernel panic, ever, except when playing with bad kexts, and when everyone was all gung-ho getting XP running on the first Intel Macs.
Now, each set of spaces is segregated by monitor, instead of every set being paired. If you're actually trying to manage lots of simultaneous tasks on multiple monitors, this state of affairs is radically better (and is the default for many Linux window managers, which have long ago addressed and solved multi-monitor problems because their user constituency is full of people in that space). In this regard, Lion is much better than Snow Leopard.
Mission Control has its issues, but it already seems much more powerful. Four finger swipe and control arrow integration makes it at least usable. I'm still figuring out how space reorganization works, but I'm at least as productive as I was with SL Spaces.
Sometimes I wonder what people think they could possibly do with legacy configurations to cause problems like the ones described. Is there a com.apple.absurdly-slow-on-3-year-old-hardware.plist you're expecting to find hidden in their ~/Library/Preferences? Pebcac is real, but if the problem exists between the majority of computers and chairs for a given OS release, then maybe it's time to redefine the problem.