How quickly do you go through tyres?

With switching between summer and winter tyres its rare for us to wear summer tyres out in the time we own a particular car; most tyres we buy are winters if the existing winter tyres don't match a new car purchase.

However just replaced a set of factory fit Conti Premium Contact 2 on my lads Fabia II HTP with just under 3mm of tread left. They lasted until the car had done 47,500 miles being switched from rear to front at around 30k (bought the car with 20k), although as stated some of that mileage was on winters.

Went with Bridgestone ER300 replacements, as the spare out of a previous Fabia II was that brand, so we got another to match. Most people seem to be negative about them but they're better than the Conti's that came off, even when they had a decent tread depth.

TP