Well, from my limited experience I would say you are right especially the fillet ability part. An unmuted square tip razor is one that you shave with using caution and always be aware of what the tip is doing and where it is. In other words you just plain can't afford to get sloppy/hasty while shaving with it. A round tip is just more forgiving if you get ham handed is all. A unmuted square tip will keep you honest.

Bob