Thank you so much,
@Steve! Great to know the built-in tele is a game changer! I could see that being the case. I'd love to "know" that Sony is working on something like this, but I'm guessing that it would be a long way off if ever.
Can I ask if you think the VR is as good on both lenses? I know I'm new to hand-holding a 600mm and it is doable, but there is a small part of me that wishes the VR was a bit "stronger". I'm not trying to be unreasonable, but I've heard so many great things about the VR on the new Z lenses and quite honestly, that just may sway me one way or the other.
I'm struggling with making sure that I spend this kind of money well! Also, please know that I am a birder at heart so it's not about "getting the shot". Rather in my case, I witness some of the most wonderful things and deeply want to do justice when documenting! The A1 with 200-600 has served me well, but I'd like to step it up. Yes, I know what happens behind the camera has to be solid and I do believe I'm doing well (knowledge, patience, talent, etc.), and there's always room for growth, but I'd like to be able to capture some of this that is beyond cropable 600mm in more detail. I hope some of you understand where I'm coming from and know I am very serious about photography. Your time, expertise, experience, and recommendations are very much appreciated!