A computer expert here on JUB once told me that ArchLinux might work best with a laptop. Do you agree?
ArchLinux will run on anything. It is extremely powerful, extremely fast, and very scalable to your hardware and your needs. But, it is designed for accomplished Linux users. It demands a certain level of knowledge about Linux in exchange for its power and versatility. If you are new to Linux, you may want to consider a distro that's a little less geeky.
...my OH wants something a little bit quicker. I have had some concerns with Fedora because they have decided not to support mp3 playing, deeming it to be a proprietary format. (There does exist a weak work-around.)
Red Hat has always annoyed me with their obsession with copyrights. Of course it is correct that mp3 is a proprietary format, but the Fraunhofer Institute does not demand a license for individuals, just commercial use (at least, that's my understanding).
Red Hat does that with all of the proprietary media formats. DVD, mp3, etc. It is not that difficult to get the usual media codecs installed, but it's not as easy as it should be.
I suggested Fuduntu because it is a Fedora fork that does not (I believe) suffer from the media playback annoyance. Also, Fuduntu is supposed to be a light weight version of Fedora that runs better on minimal hardware (which your laptop is
NOT, BTW). It uses RPM packages but the desktop looks a little more like Ubuntu than Fedora (hence the name, Fuduntu).
Any Linux distro should run well on this laptop. It is more a matter of finding what you want in terms of functionality. Ubuntu has that tablet interface (i.e., "Unity") while Fedora has gone with Gnome 3 (which is itself trying to morph into a tablet interface). Fuduntu is determined to stick with Gnome 2.x (IMHO, the best desktop computer interface ever written). Linux Mint is trying to modify Gnome 3 to look like Gnome 2 ("Cinnamon"). Cinnamon is probably an acceptable desktop, but I thought it had an "unfinished" feel to it when I last used it (about a year ago). The drop-down and pop-up menus were not aesthetically consistent and the desktop would even occasionally crash on me. But, they should have made progress in fixing some of that by now.