I was running Gentoo before. In Gentoo, you could configure everything up to the smallest details, and you had the system that worked exactly as you want it too. The cost was frequent recompiles and a bunch of time lost playing with the things.
After I swithced to Arch, I found it much easier to configure, and it required almost no maintenance. It is a great balance between ease of use and full power.
Have you found a difference in freshness of packages since you switched? I really like how in Arch packages tend to be much more up to date than other distros ( a side effect of the rolling release)
Gentoo had slightly fresher packages (I was running ~x86). But, arch packages are in principle more stable. I haven't had any major breakage with Arch for a few years now, while with Gentoo it was a norm to have breakages every month until I finally switched off.
I was under the impression that the situation was reversed. My Gentoo systems have been very stable because I take many of the masked package guidelines seriously (of course not all). Meanwhile you have Arch that changed the default python version to 3 back in October 2010 that hosed a lot of people's systems. Discussion: http://news.ycombinator.com/item?id=1808840 and my favorite quote (there are so many great ones though) from the mess:
20:20 <dash> well that confirms my impression that arch was invented by a bunch of guys who thought gentoo was too stable and easy to use
After I swithced to Arch, I found it much easier to configure, and it required almost no maintenance. It is a great balance between ease of use and full power.