See Hunter 30 website.
One of our regulars here on HOW has a website devoted to the H30. The home page has a nice description of John Cherubini written by his son, JC II. See the Related Link.As for problem areas consider that for a boat of that age everything could be a problem. That is why a good survey is so important.If the boat was not well maintained then you will find that a moisture-ladened cabin trunk will be an issue. Water can get into the coring around all the fittings, the toerails, and the portlights. This is not a Hunter issue, just aging versus upkeep. This moisture can also compromise the mast compression post and it's base. I could go on but that is why I cannot stress the survey enough.I have a 1979 H37C that is solid, stable, safe, and sails extremely well. The Cherubinis are very traditional designs with not a lot of interior room. If you spend a lot of time at the dock with four or more people then you will find it small. Good luck with your decision.