When I work with a client I will have several browser tabs open for their website, their cPanel, their shopping cart, my localhost etc.

I use tab grouping on Firefox and have a group for each client, probably four or five active clients in a given period. I have not noticed any speed issues with having so many tabs open and both memory and CPU usage is low.

I find it very easy, if a client calls me, to just open their tab group (two clicks). When I finish talking to that client, I can quickly get back to where I was. The tab groups remain when FF is re-opened.

If anyone knows of a browser with similar options, please let me know. I'm not interested in eye candy, just functionality.