... many other operators throughout the world who have been happily using the AW139 in a SAR role ...
I am aware that the UK isn't the whole story. The 2007 contract had its shortcomings and the 139 may suffer because of that as much as anything else. There are a lot of mixed messages and mis-information out there about the S-92 and it may be that the same is true for the 139. However, if there are real problems then I would like to hear the real evidence.
Space is definitely an issue for those who are used to Sea King and S-92. However, people used to 135 and Jetranger will undoubtedly think it has bags of room.
Still uneasy about those tail-rotors though.