I use st exclusively on my personal machines. Konsole on my work machine (because KDE Neon is the only Linux distro the PC support department will deign to support.) I'd be very interested to see how st stands up against other terminals speed-wise.

St feels very responsive compared to Konsole. Which maybe makes sense just because it has very few dependencies and that ultimately is oging to make for faster load times and less cpu cycles. Or maybe it doesn't so much make sense because st focuses on a small codebase and few dependencies so maybe that means they'll have less tricks like multithreading and hardware acceleration or whatever.

But in general, when I have a choice, I almost always go for whatever solution has the fewest dependencies and it rarely steers me wrong. For instance, I used dwm for my window manager for a while, but I've switched to Sway mostly because I wanted to switch to a Wayland compositor.