There is super-duper light browser you can trust. It’s Links2.
I’m always using Debian Testing with IceWM. There was the time I had 24 desktops, 2-4 GB RAM and a lot of opened websites with images from Pentax services and weather maps. Everything was controlled by few Bash scripts (open, close, update).
So, I do not understand why so many people wanna see anorexic Firefox!
And the last but not least. The Holy Grail of browsers for “low specs PCs” does not exist. The so called browsers’ heaviness defines number of opened fully loaded pages (running hundreds heavy JS apps, for example), not the browsers themselves.