I have the ATI Raven Kit. Its a headache to put the foregrip and tube rail on, there is a trick to it. You also need to fiddle with 4 screws for the heat shield and a screw for the rail. I don't think it is well designed. Was so nice with no tools.
Takes 15 minutes now instead of 2 minutes. While the fore grip is more comfortable, you would not want it on for 3 gun as it only adds weight. The mag tube will get you one more round which would help and you can ghost load a round.