I'm generally alright with add-ons that are Mozilla (or Google) 'branded', and those that are particularly well known otherwise. I also appreciate that the two you mentioned are listed as having been 'preliminarily reviewed' by Mozilla. I wouldn't go as far as to call the situation ideal though.
You're right about browser.ctrlTab.previews in any case - I must have only just tried option-tab, not restarted, or something similar when I responded to the other comment. How one is expected to dig up that option is a mystery to me though. Is it really such an unusual request?
Anyway, as someone else said, setting browser.ctrlTab.previews to true in about:config should work. For me, it successfully changes the behavior of Ctrl-Tab to most-recently-visited order, and it causes hitting Tab while keeping Ctrl held to pop up previews of the tabs, just like Alt-Tab does on Windows. If you still can’t get that to work, there is also an no-restart add-on for what you want, MRU Tabs: https://addons.mozilla.org/en-US/firefox/addon/mru-tabs/.