I'm in this crowd. I've been burned by the flex head getting a little off kilter on a stuck nut and rounding off as I gave it some force. My fault for not thinking it through, but I only use the flex head when needed.I hate flex head ratchets. Until I need one.
My other issue is the flex ratchet I have is a parts store brand and is constantly getting loose enough to flop around. I tighten up the joint every use. But I don't use it often, so its fine.