I prefer solo thinking on a problem, in slow mode; then provide solution design for review. Most of the items coming to refinement don't even require solution design, only knowledge of existing system. Yet this practice exists, which slows things down.
replied to:what is a refinement? honest question - I'm restructuring our refinements now. Like having group of people discussing 5 items in an hour gives little chances any one of them will be addressed properly, unless they are trivial.