I own both. I have an API Grand Slam and a Summit Viper. I gun hunt out of my API and it works great. I bowhunt out of my Summit and it works great. I doubt that I will buy another climber for a while. I am kinda set up. The pro's of the API is that it is comfortable. More so than the Summit. The pro's of the summit is that it is light and it is a little easier to set up and good for bowhunting.

I guess I don't have a favorite just as long as it works good.

Good Hunting.