Primes are nice to have but for me I not only want IQ but length. At times the 400 is not long enough and I can shoot f8 @ 1/1000 most days, I've been thinking of getting an extender. The weight of the 300 prime looks good but Iâ€™m over the 80-400 weight and use a Tripod. With the 400 I can go to surf beaches where the 200 was far to short. Iâ€™ve never considered the 18-200 to be old and love the IQ of it as a walk about lens. The shots above are around a 50-60 % crop.
Nikon D7000, Nikkor 80 - 400G, Nikkor 18- 200 VR II, f3.5-5.6.