I have two Z5's in 3.5-18x44, both with the BT. One is on a 22-250, so 1000 yds (for me) is moot). The other is on a 280AI. Here is my personal opinion:
If you want to hunt out to 1K, this is probably not a great scope for it. With the zero-stop on the Z5, you will be limited to about 13MOA of elevation adjustment (once you set zero). On my 280AI, I set a 300 yard zero (about 4" high at 100) and can then dial for about 700yds. Dialing for windage is not practical on these scopes (again, IMO) and even with the 4W reticle you are somewhat limited in doping the wind at very long distance.
These scopes do not have most of the long-range functionality of a Nightforce or S&B - they are not tactical scopes in that regard. BUT - they are crystal clear, super light and compact, and both of mine track perfectly. I don't use them as a hammer, but I hunt fairly hard and have not yet had one come off of zero. For a hunting scope going to 500-600-maybe 700 yds I would give them a ringing endorsement, especially if weight is a key concern in your hunting.
So it really becomes a question of what your application is - I would never replace either of the Z5's on the rifles they are on with a NF or similar. I would also never replace the NF on my heavy, way-out-there true long range rig with a Swaro.
As always, just my 2C based on my experience. - hope it gives you some feedback on your question.
