Below the line, such things as “presets” are just ready made rackspaces - nothing more.
They might, or might not fit your needs, so i see not the really great “longterm” use of them, even though they surely may provide a comfortable start for a new user.
I dare to say that if you search these forums for a special kind of rackspace, or you just ask the user base for it, you will find or get more than all those presets actually provide.
And what keeps you from building your very own “presets”, because you can export and import rackspaces in whatever state of development you want to?
As i stated above: I personally think, that it’s a nice gimmick to have some presets at hand, but i don’t consider this as “the longterm killer-feature”.