The argument that it is not easy to simply try out Gentoo (short of using a live CD) is true. It takes a commitment due to the more complex install process.
Is I today stumbled upon something like that: tere is a flavour of Gentoo which comes with a livecd installs via red hat installer and is completely preconfigured for desktop users. which might be interesting to someone. vlos
Funny, that's why I'm using Ubuntu. I've been upgrading the same installation since 7.04 without issue, even moving to different hard drives and filesystems.
Arch tends to fail me around the 6-12 month timeline, requiring manual intervention to get up and running again. Xorg upgrades are usually at fault but the more customized the system the higher the chances an upgrade will cause issues (which is ironic, since easy customization is one of the draws in Arch). The trick is to *always* read the release notes / caveats before upgrading a major package and delay upgrading if necessary. Fewer nasty surprises that way.
That's not to say Ubuntu is flawless but it does require less maintainance than a similar Arch system, where blind "pacman -Syu" is a recipe for disaster. Ideally, I'd love a system so solid that it could be set to auto-upgrade behind the scenes (and maintain itself to e.g. remove garbage from the grub menu). Unfortunately, only Chrome OS is trying to go that way right now. Hopefully others will follow soon (and with btrfs on the horizon, there are some interesting ways to reduce the risk inherent to such a system).
Thankfully I have the know how since I have used many other flavours of Linux. I've even used distros that required download of source code to install software. Very tedious. (Linux from scratch - LFS) So when you go back to Arch from there, doing a few tweaks isn't so bad to get pacman up and running again. I just wish it never broke in the first place.
What I have observed with Arch is it's slow increase in popularity, which also seems to be it's demise. Arch went from 30 or 40 something on distrowatch and now sits on 9th place. Still increasing in popularity! I'm getting a feeling that it might eventually overtake Debian and Mandriva. Back when it was in the low 30 ranks, x64 binaries were a dream come true and it was the only sensible i686 based binary distro. (personal bias) Now though, there are many x64 binary distributions available and arch is starting to loose it's appeal. Not to mention it also seems to be more problematic lately.
Arch just rules. I use it for over one year now and I had no serious problems. Yeah I was a distro-hopper previously, but now distros are distros and Arch is Arch.
Your claim guys is amateurish, the power of Arch stands in simplicity and customization, it works way faster than Ubuntu overall, not in batch tests which have nothing to do with the distribution, but rather the kernel, filesystem, compile flags and so on. Optimizing Arch is just a matter of editing the compile flags in /etc/makepkg.conf and rebuild the packages which matter with the descriptions in /var/abs - that's it!
My girlfriend is on Arch + a heavy customized GNOME and I can confess: her installation is noticeable slower than mine - possibly even slower than a default Ubuntu installation - although I didn't touch this distro for some years - I'm on XFCE, but she said that she will move over XFCE soon (after some exams). So this is the issue, one has to know what - and sometimes how - to install in the system. Linux is Linux and the dumbest distribution can lead in such tests - because the Kernel does its job - anyway.