I'm considering an upgrade from D7000 to D750 for primarily two reasons; autofocus in low light and noiseless high ISO performance. I'm mostly working with wildlife, birds, insects and flowers. The body upgrade is a significant cost for me, but also the lenses give me a concern. My Micro Nikkor 85mm 3.5G will for sure need an upgrade, but my Nikon 300mm 4D w/TC14II and Nikon 70-300 4.5-5.6G can be kept. However, keeping the two telephotos, will I loose the extra reach I gained by the 1.5 crop D7000? Of course I will, but as the D750 has more pixels, can I crop D750 pictures during post processing to the "D7000 reach" and get equal or better resolution/sharpness? In other words, will I gain anything in the telephoto area from the higher pixel number in FX without investing in bigger lenses?