I went through so many feet on my old MX510 and MX518 that I bought a huge roll of 1/2" wide industrial teflon tape to put over the feet. The newer models have much bigger and thicker feet so that’s not needed anymore, but man those old ones wore away quick.
I still feel that way about the old MX510/518/400 line. When the G series first came out, Target had a whole shelf of MX518 on 90% off clearance and I bought them all. Gave a bunch away as gifts, but they lasted me almost until Logitech made the re-release of the MX518 with newer internals. I bought a few of them and am still on the first one after a few years. I bought a 502 on clearance to see if they were any better than the MX518. Nope, so it’s now living in the backup hardware box.
Preach on, Arena was amazing at the time. The “wall” spells to make and destroy walls were super powerful and pretty unique in RPGs. I also liked the “simple” ADND2 style spells (e.g. RNG value * level fireball). Daggerfall was better in most every way other than bugs, but Arena was great. It’s hard to go back and play it though, it would need to be totally remade which might kill a lot of its charm.