http://www.btibrands.com/product/fire-control-full-length-rest/
This may be a better option for someone that wants a whole support rest. It allows you to get behind the rifle more like you would when shooting without a rest while supporting the whole rifle, but without sitting behind it, I don't know.
The problem with the X shaped sand bags is that if you want to shoot something like AR15 or even many bolt action rifles with a detachable box magazine, it is less useful. The magazine just gets in the way too much.
One of the things I have found to help me get way more steady is if the rifle is sort of gripped by the support. On the "Rock BR" the sides of the rest can become more and less narrow, pinching the forearm of the rifle just a bit to keep it more steady. The X shaped bags do that very well but can also contact the barrel which you don't want to have happen.
On my 300 WSM the bottom of the forearm is wide and flat which is pretty nice when shooting off of things. It gives a pretty stable platform, but weirdly, it doesn't fit so well into the X bag. The top V of the bag is too tight and I have to sort of wedge it in there. Smaller, less wide, more rounded forearms work very well with it, though. I have some 5 shot groups with my Cooper 17HMR from 100 yards in the dime size range and some 50 yard 22 even smaller off the X bag. Honestly, for the price, it would be my recommendation. The downside is sand bags just weigh a lot.
The 2nd half is the shooting table. Mine is ok as I stated. It has 4 contact points which means that its rarely perfectly flat on the ground. Three legs are always perfect, which is why most these days are. Also, you want the table to be pretty heavy or you need to add weight. A heavy table is a steady table. While my table is very heavy and a little short, it folds up into a very flat space which is great for storage. It's a finger smashing son of a bitch, though. If you don't have to buy a table, then don't worry about it much, but if you do, try to go to a Cabelas or Bass Pro where they might have a table or two assembled for you to sit behind. Mine is so short I really have to hunch over if I don't set the X bag on some 2x4's. It's annoying as heck. One of these days, I'll set everything up and show you what I mean. It really is a silly set up as much as I like to shoot. I should just buy a new table.
Sorry. I don't have a computer at home and have to type everything on my Iphone which is seriously annoying.
And please let me know what you buy and if you like it. I'm always interested in this stuff.