Bipod grips are not all they're cracked up to be. Many times people realize how much a hinderance they are, and this had been seen over and over operationally and in training. A local example that Dave@HuldaArms can attest to was during a Patrol Tactical course when a student had it on a rifle and wound up taking it off to drop weight and make life easier. The student wound up shooting better from prone without it.
The problem with bipod grips like the GripPod or FAB Defense T-Pod are that they are poor VFGs to start with, and they are weak bipods to end with.
The military issues the GripPod to certain units, and it's main functionality is to allow the user to put down the rifle on ground and walk away, and keep the receiver and barrel out of the dirt. GripPod advertises that you can put your body weight down on the bipod legs when they're out, but I've seen the legs break with much less force/weight applied. There are numerous instances where the legs fold and slide in unexpededly, dumping the rifle to the ground. I've also seen a couple pictures of the legs falling out completely. The GripPod is a big broom handle in size and weight, and when the bipod is out, it lifts the rifle much higher off the deck than is optimal. When you have a rifle too high off the deck, you lose stability and thus, accuracy.
The T-Pod is not very robust, and it's design is poorly executed. It allows the user to get lower, but the polymer they use is flexible and flexes under load, which affects stability.
Tapco has a grip bipod out, Much as you would expect from a Tapco AR15 product, it has cheap construction, poor durability and is made for people who don't know any better.
I've touched on this before, but from my perspective I firmly believe that developing one product to do multiple unrelated tasks breeds problems. It's also been documented fairly heavily that putting these bipod grips back together after deploying the bipod feature is difficult to do on the fly. This is very problematic for those of us that carry guns professionally, but if you are using the accessory for a multi-gun competition, it would be just as problematic. For the cost of a bipod grip, you can buy a quality VFG and get a separate bipod for not a lot more. The higher quality bipods like a Harris or AccuShot Atlas are far more robust, give far better stability, and are more adjustable. The benefit is that you don't need to run both on the rifle at the same time, and thus you can minimize weight. The added benefit with a separate bipod is that you can switch it between rifles. You can get a picatinny adapter, or just get one with a picatinny attachment.
You can do what you want. If you really want to spend the money on a grip bipod, it's ultimately your money. In training courses I've been at, and for what I've seen operationally in LE and MIL, there is a romance period with grip bipods, and that romance period wears off at one time or another. I rarely if ever meet someone that keeps one on their rifle for any length of time if they actually use their rifle a lot.
Here's a review by Nick Leghorn at The Truth About Guns:
http://www.thetruthaboutguns.com/2012/07/foghorn/gear-review-grip-pod/