I am using Vimium-FF and I don't experience any issues. What are the issues you encountered ?
There was a problem with the find command '/' [0] I had for months, so I switched to Vimium C as someone pointed out in that thread it was fixed on C already and had other features. I now see that issue was finally fixed last month.
Reading the updated thread now, I see it turned political, and I guess maybe that's why I was downvoted for linking to Vimium C.