I'm very new to photograpy so can't comment too much from a technical point of view so I'll let one of my photos speak for itself. I have this on a Nikon D750 and the photo quality is superb. It's very easy to setup and use but if you get stuck there are many great YouTube videos to refer to for guidance. It does have a little "hop" on occasion while focusing but I knew about this already. As it's minor and occasional I can work around it, especially as the Nikkor lens of the same zoom length is over 10x as expensive. Other reviews mentioned its limitations regarding low light due to the aperture range. Again, I've managed to work around this and got fabulous photos. Some comments I read mentioned a "plasticky feel" to it. I can't say I got that impression. For the money, it feels perfectly acceptable. I also have the Manfrotto Advanced 2 Befree backpack and it just about fits into that which is great. As for the teleconverter kit......I'm not sure how much I'll use it. I've only tried it once so far and it felt like the image was bobbing around a little more. Also, once on, it's hard to get off as it sticks like glue to the lens so, you take the lens off and the teleconverter wants to come too. But, you have to remove them individually otherwise, once off, the converter cannot be removed from the lens. Again, this could be a learning curve on my behalf. Overall, I'm very happy with my purchase and would recommend this to anyone looking for a max 600mm in this price range.