I have the Primos Trigger Stick tripod and really like it. It's main advantage is its light weight but not as steady as I would like. This is especially true with heavy rifles.
I needed something which would hold my heavy PB long range rifles. That's when I decided to look at the Hog Saddle tripod. I would not recommend this for spring powered or gas ram air rifles. On the other hand, these would be perfect for a PCP.
The Hog Saddle tripod and accessories are very expensive but worth every penny. I'm glad that I made the investment.
Here is the link for the tripod:
http://stores.hogsaddle.com/pig0311-g-field-tripod-od-green/ The Pig Saddle and the Hog Saddle rifle rests, clamp your rifle for a stable hold. The Pig Saddle is cheaper and made of steel. it's a little heavier than the Hog Saddle; which has a few improvements that are lacking in the Pig Saddle. I have the Pig Saddle myself and it's great despite the lack of improvements.
Link for the Pig Saddle:
http://stores.hogsaddle.com/pig-saddle-1/ Link for the Hog Saddle:
http://stores.hogsaddle.com/mod7-hog-saddle/ I already had some heavy-duty ball heads and used them for the Hog Saddle tripod. If you don't have any, Hog Saddle also sells them and the prices are comparable to what you would get at camera stores.
Link for the ball heads:
http://stores.hogsaddle.com/tripod-ball-heads/ Again, these would not be suitable for springers but are fantastic for PCPs. Here are a couple of video about the tripod.
https://www.youtube.com/watch?v=UyfRmX5YsJQ
https://www.youtube.com/watch?v=GMSgpKPfrJ0