Well I don't know, but have seen other reporting poorer results with a DS10A over a DS12A.
I have been using DS10As along with a PS561 earlier.
When I received my first SC1200 kit, I just registered the existing DS10As.
Many of the DS10As started failing at random: either signaling a low battery or a door open, but only to the SC12A, the PS561 which is still in service did not detect a problem.
I suspected a range problem, so I installed a DS12A with an external switch, farther away than the DS10As, the DS12A never failed.
I exchanged the SC12A for another, and relocated it to a more central location (the house is a 20 x 35 rectangle on 3 floors). The SC12A still see problems with the DS10As, none with the DS12A. The PS561 has no problem with either.
One thing I noticed, when the DS10As fail, I can "revive" them by pushing the "Test" button. I suspect the nature of the signal is different than on an open/close than with the "Test" button. All my door/window sensors are set to a short delay".
Eventually, I plan to migrate to all new sensors.