Did you made the very first thing to improve the overall SliTaz system responsiveness - to install properly video drivers? Your system may working well if you use just text editor and terminal, but you may notice strange lags even when you scroll the web page... If I remember correctly, to install video driver you need run the command "tazx" in the console with root permissions (available pressing Ctrl + Alt + F#, where # is from 1 to 6; then log in as root). Also you need the working internet connection, and just good luck :)
As touching this browser, well, sorry, there's only my emotions. Maybe something bad in my system, but no one application not leaves me along with the black screen yet. Frankly, this browser not looks like I can like it :)
If your needs are very simple (no modern web sites, social networks, no Youtube, etc.) you may use the simple and fast old Opera browser (install package "get-opera" and then execute as root the command "get-opera").
You may also try to use the new Opera based on the Blink engine (the same as in Chrome): use the package "get-opera-blink".
Also you can find the Firefox ESR in the forum topic close to this. The ESR version is older than the latest Firefox, but includes all the bug fixes to the current moment. It should be a bit lighter than the latest Firefox.
Other browsers I not used in the last few months, and can not say something good or bad about them.