Torquesplit - the Merlin would be good for long-range stuff but has too powerful a downwash for use on cliffs, mountains, small vessels and in urban scenarios. The stock answer to this is to say 'hover higher' but it does little to alleviate the problem and just takes the pilot even further away from his hover references. The Canadians had to revisit their SOPs and had some interesting problems with downwash at some of their HLS. The winch installation combined with the hover attitude makes winching less than ideal. The Wessex and Sea King were good SAR platforms because they offered stable, easy winching with big cabin doors and manageable downwash due to relatively low disc loading.
It is difficult to envisage a one size fits all future SAR aircraft (although that is what we have had for a while now) and most of the SAR H bidders are offering two different aircraft, one for long range/offshore and a smaller one for coastal inland use.