Welcome to the V1 club! We seem to be on the same path very very often
I recently also got the D800E, not long after you got your D800. On that topic, the D800 seems a very good high ISO birding tool so far.
Anyhow the V1 with a mid-range telephoto seems a nice light carry option compared to what we are used to on DX and FX, but yes the FT-1 is a few bucks!
As an aside, I tried the FT-1 with my 500mm way back in April but believe it or not it was too much focal length - doesn't happen too often for us birders eh? But mating it with a 300mm and it seems a nice range.