I have no experience at the altitudes and temperatures that you are looking to operate in. However I've almost 900 hours on the A119 and so a few observations.
Was at 5000 DA at 30 degrees C at MAUM in a tight confined area and I did not have to pull 'Take off Power'.
Seat confort is ok for 1.4 hours after that it's pain. We modified our seat with better profiled foam and that made it slightly better.
Fuel burn at your DA will be very frugal and if you have all 5 tanks you will have about 4.5 hours endurance with reserves, depending on the torque you use.
Cockpit layout is very user friendly.
Overall performance is the best there is, better than the 350B3 but the ride is more sports car than family saloon as with the Squirrel.
Refuelling is great, no surge like the Squirrels/135's when fuel is near the top of the tank.
All pilot pre-flights and after flights inspections are easily done but you will need a torch to see the oil levels and other items.
The small inspection doors are very good and provide adequate views to the components and should you forget to close one then there is no chance of damage in flight unlike the problems that occur with the Squirrel catches.
The tail rotor clearance is no worse than the Squirrel. The A119 has very long skids and these support the weight well on soft ground.
Without going on I rate the A119 as the best single I've operated.
The early teething problems are past. Several mods have been put in place to rectify those past faults.
I still like the overall concept of the Squirrel for what it is but the A119 is just that little bit more of a work tool and thrives on working.
It could do with an autopilot to back up the excellent SAS just for those long ferry flights to make it really easy.