We use a lot of different scopes, have most of the ones mentioned plus the TDS, Cabelas, Leatherwood, etc. etc. and I have shot them as point of aim holdoffs out to 1000 yards quite a lot.
In my opinion if there is time to crank the elevation on, your control of elevation and where the bullet will hit EXACTLY is much better than when you use a holdoff type reticle. Placing the crosshairs where you want the bullet to hit is the best aiming procedure, not holding them up in the greenery somewhere (we have even used clouds as hold-off reference points when hurling real long at rocks).
There are some exceptions - the dots, lines, hashmarks, whatever can be determined to be "on" at certain distances and then you are very accurate - if the critter is standing at that particular distance. Move him 25 or 50 yards way out there and you are into wild-*** guess country.
If the critter is relatively close, within 500 for most of the reticles I have tried, the poa/poi is close enough to kill most big game animals. I have found real nice correlation to the bars on the Horus or TDS with certain loads and hunted with them with success, out to that 4-500 yards for deer. After 450-500 I would much rather crank elevation from a good drop chart. I find that with the Horus, if I have a spotter we can get onto the target pretty quick with the second shot, but am just not impressed with doing the math to figure what line, tick mark etc. to hold with in the real world. Second shots aren't good for hunting...
A while back I had the opportunity to work with virtually all of the current reticles and shot a lot of targets at varying ranges. Like I said, some dots or bars were bang-on at a given distance, all the way out to 700 with some magnums, but what if the critter is at 765?
I would get a scope with good turrets and mildots (or the NPR2 and learn its benefits) and do a lot of shooting to develop drop charts and then to find out where your load happens to match mildots downrange. Keep that info handy (preferably memorized) for shots were you don't have time to crank on elevation.
Getting reliable base info involves calculation from a computer generated drop chart (to correlate to your reticle), which is way to frigging much math for me anyhow, or determining the actuals from shooting in the field. There are so **** many variables in hunting that I really like having drop numbers that I trust, so we go to a lot of bother to shoot good drops.
Here is an example of what I recently hunted with - did not bother to get hold-off info for this load because I wanted to shoot longer shots:
150 Gr. Hornady Interbonds
47 Varget, Norma Brass, Win. primers
YDS MOA YDS MOA
200 1.75 475 8.25
250 3.00 500 9.25
300 4.00 525 10.0
350 5.00 550 11.5
375 5.75 575 12.5
400 6.25 600 13.75
425 7.00 625 15.25
450 7.50 650 16.75
Made several very clean kills between 350 and 575 yards with this chart, including three consecutive called spine shots. Did not want the critters to get into some very deep coullees.