I'm a long way from being an expert long distance shooter, just a regular Joe Bubba on a limited budget that hunts and likes to hit the range and practice when time allows. Here is my opinion. Take it for what it's worth:
I became enamored with the idea of shooting off a tripod after reading all about it here on SH. I watched tons of videos, read a lot, and decided that a tripod could be a useful tool in the toolbox for making otherwise unsupported shots in the field. I purchased a RRS leveling base, the PIG 0311 tripod mentioned above, and adapter plates for my rifles. Added up to ~$500 or so when I got everything I needed.
My experience at the range was not as positive as everyone else's here. I didn't find the platform anywhere close to stable enough to put rounds on target. I usually shoot 12" round steel targets at 400 and 600 yards, from a prone position with a bipod and a rear bag. From the tripod I couldn't even get close to hitting the steel consistently at 400 yards. I tried sitting, kneeling, and standing. I had notes on proper form for each, and also tried many of the sling techniques for added stabilization. I dedicated an entire morning to making it work, and just couldn't. I am speaking from very little experience here. I don't know if a $1k+ RRS tripod would change my mind or not. But the "affordable" one that everyone brags about just didn't get the job done for me. Perhaps it takes a whole lot more practice to effectively use a tripod to your advantage. That's fair enough for sure. I just think the expectations needs to be set a little different, in the overall scheme of things I think a guy with a limited budget would be a lot better off spending that money on more ammo and practice from traditional positions. Seems like a lot of money for a very minimal payoff in my mind.