We have chartered with Dream Yacht 3 times, CYOA one time and TMM 4 times! The very best in our opinion is TMM. They have always treated us like family and so easy to work with. Their boats are well maintained. Of course, we have had breakdowns and they have always been quick to get a part or service guy to our boat to fix it.
Although I will say that DYC also stood behind their boats and offered us compensation every time something went wrong. They have moved up a notch since moving to Scrub from Hodges which was a gross marina.
Hope this helps.