I would never accept a 35 minute connection time. You have absolutely no wiggle room. Any slight delay in "push back from your originating gate, a backup of planes waiting for take-off, your inbound gate not being open when you arrive in Charlotte and you've missed your connecting flight. Remember Murphy's Law of Air Tavel is alive and well. It clearly states the shorter your connecting time the more likely things will go wrong. If you decide to book that short of a connection have a backup plan in place.