A.:
I personally love The Grocery Game. I admit I don't use it every week but the weeks I do more than offset the weekly fee. My top savings has been just under $50 in coupons in one shopping trip to HEB (about 30-50% of my bill).
HEB's policy allows stacking of store and manufacturers coupons on the same item. They recommend having the store coupon scanned during the transaction and the manufacturer coupon at the end of the purchase. The only problem is there are not many HEB Store coupons out there, if any.
The only thing you have to watch with The Grocery Game (at least in our family) is buying items you don't want simply because they are on sale. It's hard to train yourself to purchase before you need but that's the idea behind watching the sales. On the other hand, we have tried items we never would have before and have found a few new favorites.
The Grocery Game works well with the other websites out there. What I particularly like about The Grocery Game is that it is HEB specific and does all the comparisons to the readily available coupons (they only look at the ones from the Sunday paper) for me. I don't have to print anything off the internet and I don't have to hunt down various magazines. I'm not saying the other programs aren't good, it's just that this one is great for me and the amount of time I have to commit to the process.
Hope you have a particularly blessed holiday!