Both are great areas. However, I think HOP wins for bringing up kids and nights out.
There are open spaces - one tree hill, the rec, peckham rye etc... great schools - dalmain, stillness, fairlawn... plus family friendly eateries (Hop Scotch, Try, Le Querce)... AND not far from a good evening out at Jam Circus, the Rivoli ballroom and Babur. We moved here with kids a year ago and we haven't been disappointed! There isn't a gym, however, but one nearby at Forest Hill and various classes such as zumba, yoga and an open gym at Hilly Fields in nearby Brockley.