I think I'm like that.. I can warm up well... but normally know within 100m of a race how its going..
I think I do run better of confidence which is why I like high mileage.. I know it may not make sense physiologically but turning up to a race knowing I've ran x miles/week, x sessions/ week, gives me confidence that it'll go OK..
I definetly find a good taper now works, I never did, but think now I'm running more when I do taper and do it properly, I certainly run at my best, but I'd only do that for 5 or 6 races a year at most..
I do worry about the long term effects of high mileage are and how many runners who do 80/90/100 miles plus a week stay in the game.. speaking with a fair few older runners they seem convinced the switch to biking was a huge plus in their running longevity.. certainly now I'm at the 90/100 mile week stage I hurt more, my hips sting at times..
The other thing though, and its blindingly obvious, is being lighter.. I'm a big guy, dropping 3/4/5 kilos for a big race makes a huge difference.. but I like food and beer...