I purchased this lens a couple months ago and was apprehensive about doing so du to the limitations with my arms. Upon receiving it, I must admit I was shocked by how lightweight and balanced it was compared to the F-mount 600mm. The size of the lens is about the same but the weight is drastically less. I have had the lens out several times and find it quiet easy to carry this lens and A1 on my Cotton Carrier vest for 2-4 miles with no issues. I always take my monopod or tripod with me whenever going out with this lens. There are a few things that stood out right away when shooting including, speed of focus, speed of acquired focus and tracking ability. I have the 200-600 & 100-400mm lenses and love those two lenses. In fact, the 200-600 was what got me to leave Nikon in the first place. There are a few things I'd like to point out to potential buyers of this lens as follows.
Reasons to buy:
1-Low light shooting
2-Tracking and focus ability
3-Weight
4-Use with a teleconverter or at least the 1.4x which is all I have
5-Great image quality
Reasons not to buy:
1-This lens will not make your photos drastically better
2-This albeit is lightweight for a 600mm, it's still a massive lens to carry, haul and store
3-If the majority of your shots are 600mm or less
4-If you seldom or never use teleconverters
5-If the majority of your shooting is in great light
Having said all that, it is a phenomenal lens. There is one thing I wish were different and that is for the focus ring to be slightly more forward. I felt with the 500mm PF grabbing the focus ring was just natural and extremely easy to grab. I find this focus ring for me is awkward and perhaps its because I have the longer Wimberley foot. I don't regret buying the lens and really like it. I plan on keeping the other two zooms and use them frequently. I still say if I had to pick one lens out of all the lenses I own to be the only lens I could ever have, it would be the 200-600mm almost tied with the 100-400mm. In my opinion, these two zooms produce exceptional images and I would dare say the 100-400 is nearly as good as the prime.
Reasons to buy:
1-Low light shooting
2-Tracking and focus ability
3-Weight
4-Use with a teleconverter or at least the 1.4x which is all I have
5-Great image quality
Reasons not to buy:
1-This lens will not make your photos drastically better
2-This albeit is lightweight for a 600mm, it's still a massive lens to carry, haul and store
3-If the majority of your shots are 600mm or less
4-If you seldom or never use teleconverters
5-If the majority of your shooting is in great light
Having said all that, it is a phenomenal lens. There is one thing I wish were different and that is for the focus ring to be slightly more forward. I felt with the 500mm PF grabbing the focus ring was just natural and extremely easy to grab. I find this focus ring for me is awkward and perhaps its because I have the longer Wimberley foot. I don't regret buying the lens and really like it. I plan on keeping the other two zooms and use them frequently. I still say if I had to pick one lens out of all the lenses I own to be the only lens I could ever have, it would be the 200-600mm almost tied with the 100-400mm. In my opinion, these two zooms produce exceptional images and I would dare say the 100-400 is nearly as good as the prime.