The Tier-One Tactical Bipod is not mentioned but is definitely my favorite. Lighweight at 9.70 ounces which includes the M-Lok mount. It has carbon fiber legs and can pan and tilt. This model in the picture that I own does not pan. Legs deploy with a button.
I also have a tier one and it is great, I would say it is just as stable as the Atlas I have. Though I did expect it to come in a slightly lighter based on the stated weight on the website. It was actually an ounce or to heavier making the difference between it and the Atlas negligible to all but maybe the most anal ounce counter. Have you weighed yours? Like a few others I keep grabbing the Atlas, I also like that you have to press to pull the legs down where you do not with the tier one.
I recently bought the Spartan Valhalla and while it seems pretty awesome in many aspects it seems to have a little more wiggle to it than the tier one and Atlas. I only have a little shooting time behind it though with a .22 so I’m not set in my opinion yet.
The OP mentioned shooting to 1000 and if you’re doing that I would go with something sturdier than the Spartan javelin. You can certainly do it with the javelin and I have but it won’t give you the consistency the other more stable and heavy bipods will. Though I do think it is an awesome hunting tool even for what I would consider long range hunting.
***tried to add a picture of the weight of my tier one bipod on a scale but it said it was too large to upload. The weight was 11 3/8 ounces