Just yesterday I switched to Firefox Minefield: the cutting edge of Firefox's development. With it came new tab switching behaviour (like Ctrl-Tab).
The new switching irks me. The preview makes it milliseconds slower to switch tabs, but what really annoys me is Ctrl+Tab now switches back and forth between the last two tabs, rather than simply going forward.
It can be be fixed, just plug these into about:config:
browser.ctrlTab.mostRecentlyUsed -> false browser.ctrlTab.smoothScroll -> false
It's a good thing I can disable that, otherwise I'd have to go into a big long rant all over again.