Okay, let me first state that I am more of a believer in taking the prone position, and using a low/mid rifle-mounted BIpod, and either going straight for prone position in a long-distance shot, or, the lesser preferred indian-style sitting position.
Who care's? Just wait, I'm getting there.
If you are hunting, are you going to carry a large tripod along with you? I have found that just using my arm as an elevator, and a natural rest on the terrain, to always perform the job. My father has been taking 200 yard shots on coyote with a 1950s Savage bolt .222, dropping them--with the rifle that he has probably cleaned 3 times in it's life, using no more than the deck rail, and his hand rested, with no rear rest. He is your "average hunter/shooter", and barely at that (sorry father!), by all means. It's pick up a box of 20 from the farm store, and window watch for coyotes, for him. Although I have tried to get him to realize the potential of a heavier gun in say, 6mmBR for the deck, he's accomplishing his goal, without spending money.
Who cares? I'm still getting there.
What the OP is asking for in hopes, is sort of non-existent in the field. Heck, it's non existent on the bench. Flicking a rifle in a "lead-sled" will throw it off target. Recoil? It's off target--no ifs , ands, or butts, and the sled probably hopped back a hair on that shot anyway, causing a new POA. Even with a sled, you must be consistent yourself. The gun is allowed to move in a sled. It has padding. Pressure is applied, and you still must "settle-in" for the shot, breath, notice cheek pressure, grip, and squeeze/pull, just as you did on the shot before.
I have grown up shooting 100 meter 3-position competition with small bore, and I can never give back what the coach entrained into us. Many of us believe we need some advantage, but we may only claim to have it available.
My coach taught me a good gun cleaning, breathing method, relaxation method, and final decision when to increase that squeeze, are typically all that is needed to put the bullets where they belong. While we may use devices ourselves such as slings, too much confidence as I see it today is put off on the equipment, not the shooter.
The shooter, plays the bigger role. Always.
Have you maxed out your abilities; do you believe?
You asked, so this is my opinion, OP. Spend the $300 on ammo, and for your sight in's, shoot from a natural position that mimics the field situation. Let trigger pulls make you a better shot, not false confidence in a tall tripod that is still wobbly on grass/brush/dirt. It will not improve your shot anymore than you yourself know how to without one--to reasonable extent (off-hand is apples-oranges here, though).
If you still think you cannot do it, and that this device will be the device you need, please, at least save yourself half the money and build one yourself.
Grab a sturdy $100-140 camera tripod with good smooth adjustment and lock up (preferably with bubble level integrated). Camera pods use 1/4x20" threads. Take a cheap board, like 1x8, and build your own rest. Cut it long enough to put your front and rear rests on permanently (sandbags with velcro and stops for them for disassembly), or, take a simple jig saw and cut out two roughly square boards that have "U"s cutout you can pad with leather or felt. Screw them each tight after you mark them so they stand up (predrill and use 3 screws across the bottom of each location to suck them down without splitting). Now once you finished your platform, mate the two. Find your center of gravity you feel is best, draw a line there, and drill a 1/2" hole through the wood center. Take a brass/steel standoff that drops in the hole and threads onto the 1/4x20" threads. If the standoff is tight, throw a bolt and fender washer on top the male/female standoff, and use a wrench to mount your platform to the standoff tightly on the wood (you may need to cut the standoff down if you only find one just close to working right).
There's your ultimate portable you can just build to your own tastes using a few dollars in hardware on top the tripod. At least the tripod has camera/chronograph uses, too. Good luck.
