Strength of Pentax system :
1. Very well featured, good handling, good performance camera body for the price. So is Sony Alpha
3. Lenses that are typically designed to be smaller (and many small prime lens offerings that no other DSLR make has) Then i might as well buy a 4/3 or Micro 4/3 camera because the lens are smaller. Pentax Q even
4. Legacy support for its lenses. (even a cheap and good manual K-mount lens from 20-30yrs back will work on a Pentax DSLR). you can also use Minolta lenses on the Sony Alpha. heck, with the Sony NEX system you can even use Pentax lenses on an NEX, just with an adaptor
5. Pentax FA and DA Limited series of lenses so other brands have no limited lenses that are splendid as well?
6. Typically DSLR bodies that are designed smaller in size So is Sony Alpha