I like btop, but there are downsides:
1.) No zram/zswap statistics. (Though htop only supports zram also.)
2.) No ZFS statistics breakdown.
3.) Doesn't support Arc GPU yet.
4.) I can't disable the disk fill bars, which makes the I/O rate graphs extremely squished unless the console window is very large.
5.) Requires an 80x24 window. Not ideal for monitoring several machines at once.
htop scales all the way down to 40x8 on my TRS-80.