Well, I finally got around to trying Linux out on a spare laptop. You'll have to bear with me because I don't have the exact specs to hand, but it's a Toshiba Celeron D with 512MB of RAM and an ATI card (Mobility 7000 series?).
Distro #1: Mandriva One 2010
Mandriva failed to boot from the LiveCD. Great start everyone, round of applause. We'll gloss over that and press on.
Distro #2: Ubuntu 9.10
Attempt 1 involved the disc failing to burn 100% correctly and Ubuntu cycling from the loading screen, to the terminal, to a black screen with gobbledygook at the top, back to the loading screen again. I admit this part isn't Linux's fault, so I'll skip to attempt 2, which is when it starts to get a little more interesting.
Attempt 2 got me a bootable install of Ubuntu. The install time was pretty long but once done I started plugging away and seeing how easy it is.
My first impression was that Ubuntu is dog-fucking-slow on a machine with that spec. Considering I'd just done away with a more than passable install of XP I was unimpressed. From looks alone I wouldn't put anything between them (though it was nice to get away from Fisher-Price land) but, from the speed of it, I would have expected a user interface that operated more like Vista/7 than XP and it does not deliver that on any front. Window movement and alt-tabbing was jerky and tiresome, and I honestly could only give it half an hour before I started looking into other distros. In that time I failed utterly to get the chess program to render in OpenGL because there were two dependencies missing. Not sure why you'd distribute a program and then not bother actually installing everything it needs to run properly. Oh, and the laptop ran so hot it shut itself down about 20 minutes in, but that's probably the laptop.
Status: Abandoned for something faster.
Distro #3: Xubuntu 9.10
Having read some reviews praising XFCE's speed over Gnome and KDE, I decided that would be the route I went. Installed again and far more smoothly than Ubuntu install did, working first and picking up everything except the graphics card. Actually, that's worthy of a rant - when I did install the drivers, I started getting random black windows and notification boxes. This probably means they were right not to download them in the first place if it did work out my card, but the pissing thing didn't bother to tell me that, so I wasted half an hour installing and uninstalling the drivers for no reason, and it's hard to work Synaptic when the window keeps blacking out.
Oh, and the other fun thing - apparently my dial-up modem isn't free enough, so it initially refused to install drivers for that too. I would like to point out that most users don't give two fucking hoots about ideology, They just want things to work. So, why not install the drivers anyway and then tell me afterwards that I'm a capitalist pig? Cheers.
Other than that, I won't say that I was blown away, or even enthused, but I was surprised at how far Linux has come. Installing programs is getting close to easy, though sometimes the descriptions are a little naff, and it took me a good chunk of an hour to work out how to copy graphics files for OpenTTD from one folder to another thanks to some permissions based shit on the destination folder that I couldn't change without dropping to the terminal. I eventually copied each file one by one in the terminal using sudo. I'm sure there's an easier way than that, but I got frustrated enough that I'd had it. Installing from Synaptic rather than hunting down an installer made a nice change but I can't help but feel that repositories aren't something that Linux can keep going if, in the long run, Linux becomes more popular.
XFCE is a good replacement for Gnome and doesn't suck up processor and graphics power like a hoover, though creating desktop shortcuts is a bit odd, and took a little bit of poking before I realised you can't just drag icons from one place to another.
I think I came away from the experience thinking that there were too many little things that Windows 7 makes really bloody easy that just take one step too many in Linux. Copying files, creating shortcuts, installing games, all worked but required just a little bit more fucking about than I'd like. That's not to say I'm wiping the laptop again, on the contrary - I'll be trying a few things out. I just don't see it as a full-time replacement.
Nethack rocks, though.