There may be some air trapped behind the pucks. Remove the MC cover and sponge up a little fluid, yank the calis, remove the pads and push all the pucks back in as far as they can go. Refit the pads/calipers and pump the pads back onto the disc and hope the lever stays firm. 
There was another Hyper frt brake issue a while ago referred to as "pump up" but your issue sounds different. With the pump up issue, the brakes would work great first time or so, and then be hard to modulate, as the lever had to be pulled further to the grip before they started to bite. A number of owners felt the seals were too tight around the pucks and would pull them off the rotors too much, and so they lubed them with a rubber/silicone lube and that seemed to help keep the pucks on the rotor for consistent lever action. When your brakes go mushy, are the pads still riding on the rotor? i.e. you should hear a little hissss from the frt brakes when you walk the bike. Good luck.
There was another Hyper frt brake issue a while ago referred to as "pump up" but your issue sounds different. With the pump up issue, the brakes would work great first time or so, and then be hard to modulate, as the lever had to be pulled further to the grip before they started to bite. A number of owners felt the seals were too tight around the pucks and would pull them off the rotors too much, and so they lubed them with a rubber/silicone lube and that seemed to help keep the pucks on the rotor for consistent lever action. When your brakes go mushy, are the pads still riding on the rotor? i.e. you should hear a little hissss from the frt brakes when you walk the bike. Good luck.
