They can be great or they can be a pain. Do some looking at the archived posts here at Houzz to learn more. There are so many variables involved. A cherry or maple end-grain from John Boos could be really nice. Other woods can be more problematic. Walnut especially has an open grain that is not ideal for this application if it is a working butcher block. For a cherry or maple end-grain block, you would use mineral oil on it regularly, at a minimum weekly, to keep it ready to use. You would sand the entire surface once a year to refresh. It needs to be at least 3" thick to not look skimpy. Some people get permanent staining even with regular maintenance. If you are a person who likes things pristine and low maintenance, this is not for you.

Thanks for your input.