We tried both.

We put turf down in the back, fenced it off for the recommended six weeks, cut it and we were good to go. It took one week for it to be completely destroyed by our dogs running on it. Turf needs more work than seed to keep it nice - fertiliser and watering. We gave up in the backyard and put fake grass down. It's expensive and for it to die off so fast really really sucked.

Front we put seed down. Took 10 days for it to start to grow and probably a month before it was of a thick consistency. Other than the odd weed that came through, we had no issues with it. We didn't water it or fertilise it and it stayed green year round. It was just an inexpensive bag from Bunnings.

Personally, I love the look of turf, that instant lawn and the evenness of it but I wouldn't use it again.