Do you know if these advisors advise multiple other startups or entrepreneurs? When you meet with them individually, is it usually something fresh from each of them or do they repeat the the same things over?
All of them advise other startups and have their own companies/practices to run.
As mentioned earlier, I update them at the same time every week so they're up to date on what's happening. In fact, if they didn't make the effort to be up to date I would cut them from my Board of Advisors. I'm not sure anything really valuable can be distilled if they don't know what's happening and keep asking the same questions.