[Jon]

Quite simply if you are intending on doing a reasonable amount of macro work then a macro lens is for you. It will prove to be much more convenient in use and you will get superb results. There is nothing at all wrong with your images but the macro lens will save all the messing about swapping tubes and reversing lenses etc. You will however still find the telephoto and a close up tube has it's uses i.e. when it is impossible to get within say 30 - 60cm of a subject. I use a 100mm macro and find it to be fine but if I bought again I would probably go for a 150 or 180mm provided they didn't prove to be too bulky.
Jon