Sure have. All but two were for water detecting; all over New England, Cancun, Canada, and several Caribbean Islands. Lots of fun, difficult to please everyone all the time, but at the end of the day, everyone was hungry and tired. Lots of memories and pictures to keep me busy in the "off times". Heading for the Caribbean in two weeks, Florida in three months, and a two weeker in October - but not much detecting, if any at all for this one. Detecting with other enthusiasts is great as long as all can keep up with the pace of 4-10 hours in the water each day! It is a hectic pace to keep up with and is usually rewarding if enough research and planning goes into the trip. Imagine trying to keep 6 cars in sight and together over two to six days, areas large enough for all to detect and stay safe. Food bills, splitting resort cost and room charges can be challenging unless rules are set prior to the trip. Go for it!
A few friends getting together for a trip is one thing, but start throwing strangers into the mix with unknown or unrealistic expectations, and that opens the "organizer" up to problems they don't want or need. Pro's have liability insurance, well thought out waivers, and solid destinations and facilities.