After using Sublime for a little over a year now, I've found the minimap is not useful as a map per se, but I do find it handy for two things. First, it's an omnipresent 'fingerprint' of the file I'm looking at, and I think subconsciously it helps me get my bearings when I switch files. Second, it's a nice fat, instant scroll bar for moving around a file quickly (which, yes, I do occasionally even with all the nice fuzzy search tools).