Earlier quoted context omitted.
I'd suggest creating a new profile in Firefox and checking it again. I use Firefox with tons of tabs and don't notice any lag in tab switching. I also don't have multiprocess enabled automatically (when I tried it about a year ago or so it was slower, but it has improved quite a bit in my reading).
Google never made me do anything with profiles. It just worked.
For me, Google Chrome has always been a resource killer that's sluggish and consumes almost all system RAM (on 8GB total) with just 10 or 20 tabs. I see Firefox consuming a lot less with a few hundred tabs. While your response states your experience, it also sounds like you're meaning to say that Google Chrome is better solely because of your experience. So I don't see how such a response is helpful, overall.