I still use it today because of the plugin system. However it's annoying they update it so much many reliable plugins stopped working or don't work at all. Cookiesafe, Image Zoom and Download Statusbar being my own examples. Now we have copies into the add-on page with smaller patches that work around a solution without a proper nor official fix. Then we are on Firefox v51, seriously? That wouldn't be a problem if Mozilla supported their main feature that differentiates it from the rest. I have auto update turned off now and I'm afraid of manually updating because who knows what plugin will stop working now.