I see a huge difference using Kitty, it's much faster than other terminals.
Currently I'm using mlterm which is slower than Kitty again by a significant margin, and I still don't notice the difference in day to day use.
(xterm, st and gnome-terminal are all slower than Kitty by huge margins; of the terminals on my system (I have a lot because I tested a bunch of them a while back...) there's a performance difference in terms of rendering throughput of at least a factor of 10, and yet even the slowest once are perfectly fine for most use other than the cat large file test)
Ever since the Amiga days text rendering at sufficient speed to bitmap displays has been a solved problem, with only scrolling accelerated by the blitter, and resolution and number of bits per pixel has increased at a much slower pace than CPU performance since then.
Most X terminals use one of ~3 different basic approaches to glyph rendering anyway (as shown by redirecting them through xtruss to log the X requests they make), and their throughput still varies from far faster than Kitty (as per rxvt) to far slower, so apart from possibly the fastest ones, most of the x terminals spends most of their time outside of their rendering code.