Docglenn,
I have two Swarovski's with the TDS. A 4x-16x and 6x-24x both PH 30mm tube.
I have used the 4-16 for several years and the 6-24 for about a year. I like the TDS retical and agree with the pevious post that it is quick and simple. It has enough lines to be effective at moderate ranges (to 700yds or so)but not so many as be confusing in a hunting situation. I also agree that it is best used for big game, rather than varmint hunting for the reasons given.
I used my 6-24 last August on a Dall sheep hunt in Alaska. It was mounted to a 338RUM by HS Precision. I used it to take a ram at 503 yards. Following is how the retical works with the 338 and the load I was shooting on that hunt.
100yards = +3" (main crosshair)
200yards = +3.5" (main crosshair)
300yards = -1" (main crosshair)
400yards = -4" (first line down)
500yards = +1" (second line down)
600yards = +4" (third line down)
700yards = +8" (fourth line down)
In my experience it has been impossible to get the line to fall exactly on one hundred yard increments. I simply shoot it to establish all the yardages and how much +/- I may be at a given range. I then make up a range card that duplicates the view of the retical with a note to the side of each line with the +/- at each range. This has worked well for me and I have used it to take a lot of game in the 500 yard + range with my longest being 657 yards on an elk.
I have since gravitated toward Night Force and target turrets to dial up my yardage. Dialing up has the advantage of being more precise, which becomes increasingly important as the range increases.....or the size of the target decreases. The TDS retical does has the advantage of being quick and simple to use, so..........For big game out to 700 yards, it is great, for longer ranges or smaller game.....you should think about target turrets and dialing up your elevation.