I always try to maximise my SWU's and can upgrade all the way when I fly MEL-SFO-FRA. I used to enjoy an overnight in LA in the past when up to 24 hour stop was allowed. The new 12 hour policy has ruined this one for me and now I have to fly straight through unfortunately. Have also been known to add an extra segment to an itinerary when a stop would have been longer than 12 hours , for example I might fly into SFO to connect back to Australia but if that flight arrives in SFO too early in the morning (meaning a longer than 12 hour layover) I will then fly on to LA and take LAX-SYD instead.