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I think that's a solid choice -- I find the 16 very usable. IF anything, the wide adapter improves it, which is a nice surprise.
The real competition from Rokinon is the new 12/2 that they've announced. Remains to be seen how good it is (probably not as good as the 14/2.8, since it's a much smaller lens designed for a crop frame), but it's a step in a welcome direction.