I can only comment on the handling of the BK, but I'd love to be able to afford/justify the upgrade to a 145
With the C model tail rotor blades, the "lack of tail rotor authority" is almost a none event. At max. gross, high DA, it will need a bit of care as would most other machines, but the TR thrust is there, and effective.
Rigid ride? Well, it is a rigid rotor design, and certainly handles the turbulence more like a fixed wing than a "conventional" articulated head helicopter,
but you can use that ability to fly in areas that you just wouldn't take a "conventional" machine. Not if you want to fly out in one piece, that is!
Confined areas? The 117 is superb, if you can fit in a Squirrel, you'll land a BK, often with more confidence and safety. High tail rotor, two donks, small rotor diameter, good power reserves.
High altitude: the 145 has better engines & performance, so I'd expect it to outperform the 117-B2 that I have, which we use to land at 6000ft on a daily basis, with 8 skiers and their equipment. The roof top pad we have is a gridded deck, with no ground cushion as a result, but the BK handles that well.
FADEC: nice to have, but not exactly critical to the machine's capability, surely?
Maintenance: we have surged through remote fire operations up to 12 hours/day, and kept going with commendable reliability.
VIP transport: the short tail boom can induce a semi Dutch roll, if not handled well. CSAS will help against this, or a boot full of opposite yaw to stop the PIO
The enlarged door opening of the 145 should make VIP passenger access easier than the 117, which has a relatively small sliding door, and subsequent difficulty with entry around VIP seats.
The French have a degree of difficulty with the 145, since it slots into the sales market against the 365N/155. As the "home grown" machine will naturally be considered superior, a degree of parochialism may need to be allowed for
Hope that helps....