Having done both (SAR and HEMS) they are, on the whole quite different.
Crab hasn't done any HEMS, I might add so it could be difficult for him to compare
I can understand how SAR hours don't count, the mentality and approach is different.
'Most' SAR is long haul with some trickie stuff at the end - even then its using big a/c and fairly open spaces. HEMS (don't confuse hems with air ambulance) is little helo's and tight spaces - very tight spaces.
The regs allow for this within reason but nonetheless, when hems is played out, the actions of the pilot are much more tightly honed when it comes to judging landing zones and immovable objects which might spoil your day.
It is subjective - of course it is but the 5 "S's" come into play continuously when it comes to HEMS.......not so much with SAR.
Therefore, QED the challenges (although not as often as enormous they may be with some SAR sorties) are thick and fast - with very little (often none) time to plan fully.
HEMS pilots are little and often. SAR are big and rarely.
