Another possibility is Slackware 15.0 which is the stable release that gets updates. Available in 32 and 64 bit, runs a 5.15 series kernel (antiX 26 32bit uses a 5.10.x kernel). I have an install on an ancient Thinkpad T42 with 1Gb ram, a single centrino chipset CPU, 40Gb hard drive and radeon graphics. Chugs along nicely with Abiword, Gnumeric and Dillo. Firefox will load but is deeply unhappy.

(I install everything except the KDE and XAP package sets, and then install selected packages from XAP as I need them e.g. GIMP, xpdf and so on)

MX has more recent packages for some things though, Slackware 15 is getting mature.