Pete - Happy to assist.
topgun1984 - The Fenestron has clear advantages vs. conventional tail rotors for small and intermediate sized helicopters, but it encounters a sizing issue once you get above a certain weight class (you may have seen the photo of Puma SA330Z with the oversized Fenestron). The EC175 sits on the edge of the 'usable' size range for Fenestrons, but in the end the decision was made to make use of experience gained with the Tiger's 3-blade tail rotor, which is surprisingly quiet. Also, sorry if I confused you with the PT6 turboprop reference. The engines
are turboshafts (PT6C-67E), but they share the 'back to front' installation idiosyncrasy of the PT6A prop (which, with a few exceptions (e.g. the P180 Avanti), requires front drive). This is why the exhaust is so far forward. If you look into the AW139 program, you'll see that the engineers did a nice job in ducting the exhaust to the rear of the engine nacelle, but unfortunately this approach leads to issues with regards to power losses, heating and weight.
Hans - The EC175 proudly joins the ranks of the A-12, U-2 and F-16 in flying before its official date!
The practical reason for doing this is, of course, to avoid any embarrassment in front of the VIPs, and it's a fairly common practice (other examples including the Rafale, ATR600, ERJ145, Dhruv, Ka-60 and Ka-226).