I actually do own the Hensoldt 6-24x72 ---- S&B PMII 5-25x56 (double turn turret) ---- Swarovski Z6i 5-30x50 and use the Leica APO-Televid_50x82 Spotting scope
To compare the glass on any is extremely difficult given the different lens sizes and magnification. I can say however that I can not see anyone being disappointed with the glass in any of them – the difference is so small that you can look one day and say the Swarovski is best then the next day say the S&B or Hensoldt is best.
In Europe S&B give the best warranty (30 year) and Hensoldt the worst (only 2 year here – the factory say its because it is built for the military) S&B do not sell the military version of the PMII to the general public so the warranty comparison may not be fair.
The S&B double turn turret in my opinion is the best there is – very easy to read, very positive clicks and always on the button when doing tracking tests. The Hensoldt turrets I do not like; because they do not align correctly with the markings. I thought this was a problem with my scope but Hensoldt factory pointed out to me to a page in the manual that says this is normal!!
I prefer the non stop rheostat type illuminated reticule on the Hensoldt best I like the "push button" type illuminated reticule on the Swarovski least
If I could only have one scope from the three it would be the S&B PMII every time – it just ticks all the boxes for me.
But I repeat you cannot go wrong with any of the top 3 manufacturers – my only real regret with the Hensoldt is that I did not buy it from your side of the pond and get the lifetime warranty.