I traded a little-used Canon lens toward the purchase of a very-nicely-preserved pre-owned Nikkor 70-200/2.8G VR. I was seriously considering the newer Nikkor 70-200/2.8G VR II, as Nikon USA was running a $200 point-of-sale instant rebate, during June, but I decided that 70-200/2.8 was the least important of the Trinity, for me, as I have several excellent prime lens choices within the 70mm to 200mm range, with aspirations of acquiring more telephoto lenses for birds and wildlife. The newer 70-200/2.8G VR II does have better edges and corners, with FX cameras, but that is more important, for me, with the wider two members of the Pro Zoom Trinity.
As mentioned in my older thread, I bought my Nikkor 14-24/2.8G and 24-70/2.8G within a very short period of time, last year.
Interestingly, the Canon lens I traded toward the 70-200/2.8G VR was one of the Canon Pro Zoom Trinity, an EF 16-35/2.8L II, though the Canon Trinity concept has been in a bit of disarray, with the new 16-35/4L IS being very sharp across the frame, and f/4 being good enough for many professionals to prefer it to the f/2.8L option. Plus, the excellent, expensive, new EF 11-24L changing the whole equation, for those with enough purchasing power.
I do not aspire to aquiring a complete set of Canon pro-level zooms. I rarely seem to want to shoot wider than about 28mm with my Canon cameras. Canons seem to be my bird/wildlife cameras, while I use Nikons for pets and people, so it makes sense to have the Nikon Pro Zoom Trinity.
Canon 5Ds R/7D2/7D/5D/40D/1D2N/M3; Nikon F6/D3s/D700/FM3A/1Dx/Coolpix A. Lens selection undergoing changes; some favorites: Zeiss 2/135 APO Sonnar, Canon 100mm f/2.8L Macro IS and 135L, Nikkor 14-24/2.8G and 24-70/2.8G.