As you said it varies depending on the event you're taping for as well as the depth of your training base and fatigue when you start the taper.
Personally I have best tapering results when I dig a pretty deep training hole by doing a few hard long days in the saddle before tapering. My best results have come when I do those big days about nine or ten days before my event, get myself really tired then take a few days completely off the bike before doing a lighter week with some extra intensity but less overall volume in the final week leading up to the race. That works much better for me than tapering from a steady training volume and personally I wouldn't take a rest week before tapering.
Tapering also works best for me (and others I've worked with) from a fairly high overall training load. IOW, I doubt the rider who's worked up to say five or six training hours per week is going to see as much rebound freshness from a taper as the rider who's putting in two to three times those hours weekly. In power terms I don't think it makes much sense to taper when your CTL is below say 60 or 70 but makes a lot more sense for the athletes sustaining a CTL of 90, 100 or above.
The other basic tapering premise that seems to work for me is to taper more for short intense events and taper less for long endurance events. IOW, freshness is really important for short punchy races like crits and track races but fitness is really important for really long events. Tapering buys freshness at some cost to fitness as you tradeoff training for additional recovery.
YMMV,
-Dave