The biggest for me is using multi pane/tab with abilities to simultaneously write command on every tab. It’s very handy when you just want to ssh into multiple instance and execute same command. But i’m not sure that Konsole or GNOME Terminal can already do that?

Also my another newer one that highly customizable is WezTerm. It’s multi-platform including Windows and Linux. I have been using it on macOS and loving their simple config file.

Terminator is def my fav. It’s pretty much on par with iTerm2 in macOS.