I can't speak to personal experience with the Z6 Zeiss except that when I picked one up, the store owner (who sells a lot of high end brands) pointed out that the amount of tube to work with when mounting the scope is somewhat limited when compared to some others.
I in fact purchased a K418 4.5x18 with the target turrets and have not used it yet. (Still NIB). I have decided to instead mount a NightForce on the rifle soley because it has illuminated reticles. The trade off however is a considerably larger and heavier scope which I will have to lug around the mountains of MT when I go hunting there next. I have owned Kahles scopes and recommend them very highly. Optics are every bit as good as Swarovski and probably slightly better than the Nightforce but not much. (Obviously, since I'm looking for a NF myself.) I currently have a Kahles 3x9 Multizero on a Bob Hart .325WSM rifle which I am very pleased with.
I have owned a Zeiss scope (4X Diaytal C) in the past and my only complaint was that the eye relief is very critical on the one I had. The "zone" for full sight picture was small so mounting the rifle quickly with thick hunting clothing vs thin summer clothing was a little tricky. It bothered me enough to get rid of the scope. That was several years ago however and that may have changed. I did however, recently look through a Zeiss Conquest (nice optics) and it too seemed to be a little touchy.
Just some things to consider before purchasing any scope.
Like I said before, I still have the Kahles K418 NIB which I am willing to sell at a very reasonable price (try finding one ) if you're interested. Good Luck.
Just a quick follow-up. You also may want to check with Zeiss, but the ballistic turret might only be available for the huge 56mm model. I remember there were some features which were only available on that model but I can't remember if it was the ballistic turret. By the way, their ballistic turret is almost identical to the Kahles Multizero feature except I think the Ziess has one less preset than does the Kahles. Hope this helps.
LOL don't worry about it, it's all clear now, i have a bad felling about this maybe no one is buying swarobskis Z6 for some reason, i hear some time ago some one complaining about swarovski reliability, the guy said that the scope couldn`t handdle the recoil of a 30-06 but that's just one guy saying someting and i prefer ask to the shooting coomunity to be sure if there is a real isue in swarovski's z6
I actually like the Z6 but the tube length issue was a concern of mine. Additionally, the price was exceptionally high and they only offered some of the options on the huge 56mm version and not the smaller, more practical 50mm model. Too many strikes against it coming out of the dugout. I will however say they are good quality scopes and I find it hard to believe they wouldn't stand up to any reasonably recoiling rifles up to and including the 300 & 338 Win Mags. Beyond those calibers, you probably need to be thinking about durability issues with any scope. Again, I have a Kahles K418 NIB if you're interested. Good luck.