This is the must-have feature that keeps me using Firefox -- especially when I'm doing research, which has a naturally tree-like pattern. Apparently, from the Chromium bug, it's a dealbreaker for lots of other people as well: https://code.google.com/p/chromium/issues/detail?id=344870
It helps that Firefox offers to change to an existing tab when you try to open the same page in a new tab.
Another suggestion is to not manage it. I create tabs all the time, and often have many similar tabs. There's no need to manage it, only to clean up once in a while.
(I like many tabs. A few weeks ago I performed some tab-cleaning -- 550 tabs were a bit much, as it made Firefox start slower.)
Personally i just use it for things I would like to read at some point, instead of filling up my bookmarks with 50-10 entries every day.
>It helps that Firefox offers to change to an existing tab when you try to open the same page in a new tab.
Disabled that as soon as it was dumped on me. There are an almost infinite list of reasons to have multiple copies of tabs.
Honestly, I cleanup every week or two, and it works fine. Windows are by category of different things I do, and I tend to leave frequent sites open all the time.
The TabPolish Chrome extension implements similar behavior (in a slightly different way; it doesn't hook into the suggestion menu, and duplicate detection is per window, rather than per browser instance).
I find it essential to manage the mess that is my Chrome tabs.
I deal by creating multiple windows, ideally one per general topic/use case. This works great with Chromium because you can easily drag multiple tabs between windows to organize things, and the shrinking tab bar encourages you to close things you don't need. Doesn't work so well in Firefox, where you have to manually drag each tab over one by one, doing so is kinda glitchy, and the scrolling tab bar makes it easier to just fill a window with a ton of unrelated tabs.
Although I don't get anywhere near 200 tabs, I hit the same type of UI management issue. I use contextualized "sessions" using panorama in Firefox (Ctrl-Shift-E). I have 10-20 tabs per context, and somewhere between 6 and 10 contexts. Between Panorama and TreeStyle tabs (a plugin), everything is neatly organized.
Panorama is a life-saver if you have to context-switch between projects regularly.
TreeStyle, really, I use more as a means to move screen real-estate to horizontal usage on my laptop's 16:9 screen. Tab organization is a side benefit.