I love my spot hogg triple stack. Better than the double pin in my opinion because you can adjust each individual pin to your bow speed and your desired distances. The double pin is fixed, so your yardage gap just is what it is. You may get lucky on a double pin and your gap works out to be 20 yd for top pin and 40 yd for bottom pin. Or they may not be round numbers, and that may bother you
The triple stack is heavy, but you can customize it to get your exact yardages and desired pin gaps. Quick ranging is a little easier too. If an animal is somewhere between 20 and 30, as long as you cover the vitals with both pins, you’ll be good to go. With a double pin, you may only be able to get 1 pin on the vitals and then you have to guess more with your hold overs. The only downside, other than the weight, is that the housing is kinda ridiculously huge. It’s great for having a big sight picture and allowing light in during low light situations, but it will be less accurate than a smaller diameter housing
Finally, aside from your bubble, my eyes and brain also seem to pick up if the pin stack is canted at all to the side or if I’m torquing the bow (as I’d then be able to see the side of the pin housing). I couldn’t tell so easily with the horizontal pins. So I find myself automatically/ subconsciously holding my bow more level than I did with horizontal pins