Posting things hourly is excessive and over the top. I question too that this must be an incredible interruption to the vacation. Seems really sad to me that they would feel such the need to do so. It is just my opinion but I find there is a fine line between posting about holidays for the purpose of simply keeping people informed and that of a 'look-at-me' intent.

Sometimes we fall into the trap of 'too much information'.

Consider this that it would be much more pleasing to sit down with and tell people all about your fabulous time in person.

If you feel the need to keep in touch while away, might I suggest a single post with one or two pictures that sum up the day?