Oddly, I also use FF on a 16GB Mac and experience none of those slowdowns that you mention. On my work machine, FF typically has around 100 tabs grouped into 4-6 tab groups by project and it is solid.
I do find that some websites end up using 1GB+ of memory if you leave them running for an extended period of time (looking at you MacRumors forums) but that happens on Safari and Chrome, too. HN is usually the safest one that uses the least memory. Sites with lots of ads load all kinds of crap and can use surprising amounts of memory.
I do find that some websites end up using 1GB+ of memory if you leave them running for an extended period of time (looking at you MacRumors forums) but that happens on Safari and Chrome, too. HN is usually the safest one that uses the least memory. Sites with lots of ads load all kinds of crap and can use surprising amounts of memory.