I've been reading this forum for a while and I think it'd be the best place to ask for an advise.
I've been running Linux on my main PCs since 2001 when I was (still) using Slackware from the '90s days.
Every PC I've got never run it's original shipping OS. I used to turn it on, check the BIOS booting options, slip a Linux CD inside and then install it. No four-color-flag, then.
I am currently running Kubuntu 10.10, but have tried also Ubuntu, Gentoo and Fedora. None satisfied me. This is why.
Mine is an ASUS G1s laptop, T9500 (x86_64), 4GB RAM, 320GB SATA@7200rpm I use 50% of the time as personal computer (browser, CD/DVD burning, OpenOffice, ...), 50% as a development platform (C/C++, Postgresql, ...). I would say it's quite powerful for me.
First point. Responsiveness.
It's a nightmare. Copying large files back and forth to a couple of USB disk will make the system unusable, even to edit a .cpp file with vi.
The same happens when burning DVDs or unpacking large tar.gz or rar archives. I can run ionice(1), but only at the CLI, no (easy) way with the GUI.
Second point. GUI.
At the moment I use KDE, but there's no problem to switch to another DE.
Both KDE and GNOME as shipped by Ubuntu are either buggy or incomplete. At least to me. I'm not sure whether all these issues are in the mainstream or have been introduced by the Ubuntu packagers. I used to be happy with KDE v3, but that's not available any more.
So what I'm looking for is an OS with a decent responsiveness even during large I/O loads (I don't mind if the copy will take 5 or 6 minutes, but I do mind if I cannot type code into vi).
Then a decently complete DE would be greatly appreciated.
You want an OS similar to Slackware, with some package management capabilites, relativelly fast response and you can also build your own packages?
Try Arch Linux... I also did a lot of distro-jumping until I found Arch...
I started my Linux "cruzade" with Ubuntu (about 5 years ago); then, insatisfied with GNOME (seems like a Win2000 environment), I changed to PCLinuxOS (a KDE-based distro)... But, I found it a bit "conservative" and then, I switched to Mandriva Cooker (other KDE-centric distro). I used it until the end of 2008, when I found Chakra Linux (which was at the time KDE4 + Arch Linux, now it's a separated distro ).
I wanted to try Arch, but without a lot of hitches... Since then, It's my distro of election, although now, I build some of my packages, and removed the KDE4-related ones (KDE and GNOME are somewhat resource-intensive, but less than DWM (Windows Vista / 7 GUI interface)), replacing them by LXDE + Compiz + LXDM...
I like Arch because it has a very nice Wiki section (with lots of documentation avaiable), it's relativelly easy to maintain (creates a package cache if something goes wrong), doesn't have a release cycle, and it can allow me easilly to intall packages, or build my own ones if I want more control in which dependencies I install in my system... (so, I have less bloat).
p.s.: If you want to try a lightweight Arch live CD, try Archbang
I recommend Mint, OpenSuse or Debian as user-oriented distros. If you need switching library versions, manually adding parts - Arch or Gentoo, but both would require your knowledge of the system. Latter will allow much broader package version choice.