The overhead and performance hit aren't worth it for me in general since these browsers are set up to enforce secure connections as long as you don't override it. And I don't have to worry about government level website filtering. I do see the value in tunnels for stopping the ISPs from tracking and selling the list of sites you connect to, but I'd rather set up my own proxy for that if I felt it was worth it. It's easy enough to set up a web proxy on a small, cheap, remote VPS or pay for a trustworthy service with no logging so the ISP would just see that connection and it would be way faster. I don't see much value in using a Tor browser otherwise anymore now that HTTPS is ubiquitous and secure DNS exists, unless you want to access things not on the public web.