I'm surprised that there has been no discussion about this new pricey piece of glass that was finally announced on May 14th. I am really, really tempted to buy this lens for an upcoming African safari. The MTF charts look impressive and the limited reviews thus far have been very favorable. Most of the discussion on other forums boils down to bitching about the price. However, it is the built-in 1.4 teleconverter that keeps pushing me over the edge. Your thoughts?