T-25 mins normally, maybe earlier if I am Row 1 Club Europe with lots of hand luggage and a full flight.

As long as you know where you are going, and you know how long to get to each gate - anything earlier is just a waste of time that could be spent in the comfort of the CCR.

On longhaul, even flying F, I often arrive at the B/C gates just as the final few passengers are filtering through the gate.