I happen to have all three of those scopes here and have used them for several years. Here are a few thoughts, for what they are worth... Happen to shoot three Kahles TDS and have shot several more with the company folk. Have never seen any problems, used the turrets a lot and shot the TDS on in-lines, slug-guns and several rifles including a nice HS varminter. Also shoot several Nikons, both shiny and matte finish, very sharp and bright images, no problems to date and they have been all over N. America, mountains, arctic, Mexican border, very heavy use on range also. Have a couple of Leupolds and they are like a rock, very reliable but not flashy - they are "can't go wrong scopes".
Sharpness - resolution - in these scopes I would have to rate them in this order Nikon, Kahles then Leupold but that does not mean that the Leupold is not sharp, the others are a tad sharper. This is only relative to my scopes and my vision.
Brightness - Nikon and the other two about tied - same comment re my particular scopes and my eyeballs.
Adjustments/turrets - have not had any problem with any, although I like them in this order Nikon, Leupold, Kahles as far as "feel". All have been as accurate as you can expect from that grade of hunting scope
Finish - Kahles is a softer matte, nicely finished. Tne Nikon and Leupold are also good looking scopes, about equal in apprearance.
The Kahles has a fast-focus eyepiece, the others do not and this is a very good feature, as long as you do not use Butler Creek flip-ups
Nikon & Leupold are duplex style reticles, the Kahles's have TDS and it is worth having. Very simple to use (not sure you want to let yourself get too carried away with the instruction manual and "factors"). Just zero it and put some target downrange and see where the bars fit relative to where your groups hit. Bottom line, you have constant aiming points in the scope (at a given power, or they can even be changed by indexing the power ring), gives you simple hold-offs within range of most hunters (5-600 max).
I have shot the TDS in Swarovski and Kahles since it came out and rely on it for some types of hunts - particularly on my in-line muzzleloaders for shooting out to 200-250 yards.
TDS stands for TD Smith, retired airforce pilot who is simply bigger than life. You would NEVER forget having met TD. Easily one of the most amazing individuals I have ever met.
Goo luck on your selection - you are in a good dollar value range, the scopes are going to give good performance and should last a long time. Talk to www.swfa.com