I'm now halfway through Series 3. It's been excellent from the get-go.

I already know upcoming plot developments, and how the season ends, and "whodunit", as I recently cheat-read ahead, what people wrote at the time of original broadcast. That in no way lessens my enjoyment or appreciation any.

Very good acting, strong and complex story line, terrific casting, wonderful locations, top-notch characters integration, etc. Through the point I've seen, which is Episode 3, has all been win-win!