I'm considering starting a map with the structures option disabled since I don't really like the villages and the abandoned mine shafts. The mine shafts especially, seems to take over all underground areas to a point where it is hard to find any natural cave systems.
I also realized that ravines, which I like a lot, will still be generated when structures are disabled.
The one resource I know I will miss are melons but giving 1 melon seed as server admin should fix that.
So what other resources of importance will be impossible to find when structures are disabled?