I can't comment on the recent Kahles models with the multi zero setup, as I don't have one. However, I still do have a Kahles 3-12x56 (steel tube) that I bought in about 1985.
Earlier I had a Kahles 3-9x42 on a rifle that was subsequently stolen, but it had good clarity and was also reliable.
I originally bought the 3-12x56 scope to put on a varmint rifle (.17/222 mag imp) that would be used mainly spotlighting foxes at night here in Oz.(ie 56mm obj) However, the thick reticule on the higher powers made it more suitable for larger targets than rabbits and foxes at longer ranges, so I transferred it to a 25/06 AI, and it has remained on that rifle since about 1988.
This scope has proved to be very robust and strong, and has withstood several very severe impacts, but suffered no visible damage, and still maintained the zero.
Clarity on this Kahles is good, but slightly inferior to a Nightforce 8-32x56 that I bought about 15 years later. I expect that it will still be working reliably in another 20 years time.
Unfortunately the exchange rate with the "Ozzie" dollar has soared, and now they are very expensive and other scopes probably represent better value for money. Hope this information is of some help. Brian.