I am going to Gridlife this year in June at Gingerman. Unfortunately I did not get granted access for a media pass, but I still plan to shoot as much as possible.
I have my 300mm f2.8, but it is the very old Nikon version (first AF model - my 70-200 VRII is exponentially faster at AF) and it seems soft compared to what I would expect out of a 300mm. I have been considering renting a lens, and had my friend tell me that he thought 200mm on FF was long enough when he shot last year). That seems awfully short from what I would expect, but if true it would allow me to rent the 200mm F2 that I have lusted over for years.
The 400mm seems like the default motorsports lens, but that is extra large, and extra expensive to rent. I would hate to rent the 400mm when I already have a 300mm, and it ends up being a bit too long.
1) Rent 200mm F2, use my 300mm
2) Rent 400mm F2.8, use my 300mm
3) Rent a newer 300mm F2.8
4) Just shoot with what I have since I don't have access anyways.