Ummm, maybe I'm wrong, or maybe I'm just picky:
As soon as you're no longer "in sight of the ground" you have to be IFR. So there's no such thing as VFR on top.
As for operating a single in IMC. I'm perfectly happy to as long as the cloud base is a reasonable distance from the ground (2-3000 feet) I want to be sure that if it all goes quiet I'll have time to find a field and land in it after gliding through the cloud. If I were flying over wide open flat terrain, then I'd probably reduce my minima.