So I tried an experiment. I downloaded the LXDE environment -- supposedly a very lightweight and faster system. (This wasn't hard -- the metapackage was in the software manager program.) Then, using the same approach, I downloaded Chromium, an often faster browser.
And guess what? It is faster, quite noticeably so. Probably I should have tried this before trying to download and burn copies of Peppermint and the Debian-LXDE distros. But hey, it killed some time while I rested up from my travels, and it's good to have speedy little devices around the house.