I have often heard it said that one should always be within gliding distance of the field and many people claim that they adhere to this.Surely the only way to achieve this is to always use a glide approach as any need for power means that you are beyond gliding distance,so unless you intend to always carry out a glide approach the whole argument breaks down late downwind.
SSD...I too have taken a bite out of my seat on the approach to 27 a couple of times and not with my teeth I can tell you!! The only other option is a swim in the ship canal.
P.S. my preference is to use a glide approach as much as practical but so many times I am forced to abandon it due to other traffic..ATC extending downwind etc..so I think the best policy is just to stay as tight as possible under the given circumstances and not worry about it too much afterwards,after all,in a normal powered approach,the only time you could feasibly glide back to the field is from the end of crosswind to the point on downwind where you would turn for a glide approach.
Best Wishes,
Beethoven