Just after opinions here but I know ultimately I'm the only one who can make this decision. I just bought the 12-40mm F2.8 (which I now love) during Boxing Day sales and I was planning on buying the 40-150mm in a couple of months time (after my wallet's recovered from Xmas). However, I can get a deal on it and the MC14 until tomorrow (under $1500 for the Australians on here). It's one of those purchases where I probably shouldn't, but I can make it happen if it's a good deal. Is it worth it? I'm mainly into outdoorsy stuff (urban, nature, forestry, animals etc). Also is the teleconverter worth it if I can afford it?