If you're doing this, then make sure to order a reverse lens ring to compare the fourth option - some folks reverse their wide angle lenses to get ultra macro lenses. In fact I'm wondering whether I can find a good old prime wide lens for this very purpose. Of course, it's all manual, since the contacts of the lens are on the wrong side :)
I haven't found it to reduce the quality much, but you do have to go much closer (at 1:1) so easier to mess up I think.
I'm working on a post comparing the three set ups — just lens, with filter, and lens+filter+extensiontube
If you're doing this, then make sure to order a reverse lens ring to compare the fourth option - some folks reverse their wide angle lenses to get ultra macro lenses. In fact I'm wondering whether I can find a good old prime wide lens for this very purpose. Of course, it's all manual, since the contacts of the lens are on the wrong side :)