Seasons 1 and 2 were very enjoyable and gave them a 9 and an 8 respectively... albeit a few nuances here and there.

Season 3 overall was rubbish. The main story arc from the start was a Good concept to explore this time around and they handled an important social change very cleanly and tactfully, but the writing and forced story events were so poorly done it completely pulled the series down. Either the writing team had been completely replaced, the writers never had their work checked over, or those who "approved" such terrible scripts were not interested in providing a quality show and more interested in cutting corners and pumping something out quickly, regardless of the negative impact the poor writing would bring.