Hi guys. You should probably look at the posability of internet failure. If the link is not essential or critical then yes go for the low cost option but as an ex event engineer the more pc's and odd boxes you use will impact the reliability of the system. There are a number of RF hire companies that are able to supply bidirectional audio and video links that historically are very reliable. You would also have capacity for talk back and so on. Have used Broadcast RF in Dartford several times. Good but the cost may make you want to cring. M
