I too have just moved completely to Arch Linux on my laptop to simply be on the bleading edge of linux and it's supporting programs. I also didn't like unity and the way ubuntu was going. Jumping the ubuntu bandwagon was the best thing I ever did for my laptop, which now is also my main rig. You have a good point with gentoo as well, that distro is one that will truly teach you how linux works. Arch has been a fantastic stepping stone for me. Gentoo is the next stepI've recently ditched anything Ubuntu based for Arch. Ubuntu builds had a weird issue with the wireless card in my laptop. It would work at home no issue, but I couldn't route out on the guest network at work. Both wireless connections are standard WPA2-Personal. Installed Arch and all works great. So either the ath9k drivers in Ubuntu derivatives are crappy, the kernel in Ubuntu (3.0.x) has an issue with the driver, or perhaps even both.
Arch works like a champ though with kernel 3.2.8-1 and the ath9k driver. Arch overall is faster too due to the lack of bloat. If Arch ever gives me an issue I think I'm going Gentoo after this. I've always been a Windows guy and then I found Android which led me to dive into Linux more then I ever did in the past and I'm sad to say I should have jumped ship many years ago because this is just too damn fun!
Between the two you're right. I like xubuntu as well. I almost went with just that distro over archlinux. However, I'm very glad I went with arch. I learned alot more and am still learning how things work. Gentoo may be my next projectxubuntu, that or lubuntu, but xubuntu is better imo