I can very easily see myself gearing up something other than a Mooney, but I can't see gearing up a Mooney on a normal flight 'cuz it just won't slow down to land without the gear out.
However, if just doing pattern work or some other sort of flight where you'd have to be slow as it is, that's not the case and it opens up the possibility of gearing up more easily.
As for gear warning horns, like everything else, they fail. I was all proud of myself that I hadn't even made the horn go off since I was getting checked out in the plane, and then one day for the heck of it, I pulled the throttle back at altitude, dropped the flaps, kept pulling power, slowed down... And finally realized that the horn was inop. Sigh. It's one of those things you never expect to need, you feel safe knowing it's there, but if you don't test it, it won't save you when you have a bad day.