Mr slani, you're preaching to the converted here, I've had excellent life from square taper, this bike came with hollowtech and I want to live with it and see how it is.
Except for lower mass of HT2 BB and crankset - it is worse. The proposed extra stiffness is something that, at least I, can't feel and notice the difference, but the extra maintenance is felt.
Annoying noise starts rather quickly. Then the bearings still have a lot of life in them, just the noise. But not nearly long lasting as the square, or Octalink 2 BBs.