I was thinking about buying iStat Menus or iStatistica Pro, found this thread while searching for something like reviews or comparisons.
That price might make me buy iStat Menus, but now I also wonder if they will release a paid update soon.
I LOVE iStat menus. Be aware that the Big Sur release has several bugs and omissions on Apple silicon - many sensors don't yet display, battery shows 2% health and that it needs to be serviced, etc. Company is aware and working on fixes. Still provides the menubar stuff just fine and I'm sure they'll tune up the other weirdness quickly. Highly recommended product.