This really depends. The marginal cost of "what version is this box running, why doesn't this work, oh we don't have that tool?" could be very high on something like that.
I mean remembering, that the net is full of slow brute-forcers and the like. Just because it takes a few days to run through all the exploits doesn't mean that someone won't do it - that's thinking of security in human, individual terms, as though the threat is targeted rather then general.
But here is where it comes in handy: If you have your version numbers out there in some database and a 0 day for that particular version hits then you're hacked. If not then you might be able to patch your system before a breach happens. It's no guarantee but since it costs very little and gives you possibly a bit more time when you need it badly it does not hurt. Obviously you need to cross all your other t's and dot the i's too.
And if you need your headers to tell you what versions are running and what tools are installed you are doing something else very wrong.
I mean remembering, that the net is full of slow brute-forcers and the like. Just because it takes a few days to run through all the exploits doesn't mean that someone won't do it - that's thinking of security in human, individual terms, as though the threat is targeted rather then general.