My desktop has over 2000 tabs open in Firefox. Memory footprint is slightly over 3 gigs. I usually manage to keep the laptop tab count under 1000. Honestly I think you're the first person I've ever heard praise Chrome(ium) for gracefully handling high tab counts.
I'm not a fan Mitchell Baker or many of the ways Mozilla works these days. But in the pulling crap department, Google and Microsoft have given Mozilla a very low bar to clear.