I may be biased because I formulated it, but, I've used Absorb Plus to both gain weight and as a daily supplement shake. It's really handy for me because I can't swallow pills, so I just empty all my supplements into a shake each day (Berry Fusion is my favorite flavor) add flax oil, and it's a tasty way to get superb nutrition every day.
I'm now pregnant with my second child and I have one every morning with all my prenatal supplements as well. Having drunk other protein shakes and mixes for years, you can't even compare the taste difference. Most of the others are really nasty tasting and I've had to force myself to drink them.
Absorb Plus actually tastes good! In fact, I find myself craving it and my 2 year old son often asks for a 'milkshake'. Which reminds me, it's great to use for kids so you don't worry if they haven't eaten much that day, or when they're sick. You just whip up 1/2 a shake with flax oil (I put extra Vitamin C in calcium ascorbate form in it if he's sick to boost his immune system) and he thinks he's getting a special treat. Again, this works, because the product tastes so good!"