Sony a57

We know camera models are going to be replaced like cell phones — at least twice a year, more if the manufacturers have the cash flow. Sony seems to be innovating, not that innovation is the sole determinant. What is? Going forward, the one with the best feature set for small mirrorless or SLT cameras. A good EVF, focus peaking for manual focus, a reasonable array of quality lenses at a reasonable price? At the most I can afford two cameras, one more or less heavy duty model — the Sony Alpha a57/77 — and a walk-around — the Sony NEX 5n. I can share accessories and human interface similarities between the two.