I've read and seen great stuff from this lens, and for its magnification its unique inthe slr world isn't it? So does that make it the best macro or are there others that have awesome/exceptional qualities to them?
love the shots guys!
There is no "best" macro. There are many different macros for different purposes. IMHO the MP-E 65 + MT-24EX is the best general purpose macro for small insects. However, it certainly isn't the only macro I depend on. The following are also great macros I use and each has its specialty.
(note: for those curious I discussed them more on a friend's blog - http://www.ronmartblog.com/2011/11/today-im-happy-to-have-blog-reader.html
100/2.8 IS Macro - great general purpose macro, leaves, flowers, small objects
TS-E 90 - probably best general purpose macro for flowers. Tilt provides a lot of flexibility.
TS-E 24 II - great for broad views
300/4 IS - great for dragonflies
70-200/2.8 II - abstract subjects
70-200/2.8 II + 2x III - provides more magnification + becomes a different lens
In terms of the MP-E 65, it is an awesome lens but there are ways to go even higher in magnification or improve the resolution. At 5x I have seen evidence that a Nikon CFI 10x .25 10.5 mounted on a 100mm/2.8 macro is sharper. You can also mount other microscope objectives to go further. I am currently in the process of doing this and I hope to provide some examples in the next few weeks.