With Clear, you should definitely make sure you have a conversation with their technical people. I don't know the gory details of how they share their bandwidth, but it's not inconceivable that if you're banging away on all four Clear devices, that they'll each get 1/4 of the nearby base station's bandwidth. Conversely, they may be able to offer you "commercial" grade service at some higher price point, with a single base station from which you can service the whole building.