I just got the newer version of Firefox (v157.0) and I'm amazed at how snappy it is. It feels like Firefox does when you have 0 extensions, except that I have uBO and a few others.

It used to feel so sluggish, pages took 500ms or even 1 second to display anything after typing the address, but no more; they render almost instantly.

A very nice surprise indeed!

If you left Firefox because it was too slow, now's the time to ditch Chrom{e,ium} and reign Google's chokehold on standards and utter contempt for privacy in!

Ran some benchmarks on an X230 (i5 3rd gen):
FF 156
speedometer: 3.27
jetstream 3: 65.3
motionmark: 456.52 60fps +-7.50%

FF 157
speedometer: 7.16
jetstream 3: 68.49
motionmark 593.57 60fps +- 8.93%

The speedup is quite noticeable