Any EC155 drivers ?  

The EC155b1 has basically the same fuel burn rate at most operating weights. Yeah, some pilot might want to respond that the fuel burn rate is higher or way higher at higher weights but it is more negligible than true. The biggest thing you will see is cruise airspeed. The cruise airspeed difference you wil see between 2 pilots and lets say 2 pilots and 5 passengers will be a drop in cruise airspeed as high as 7 knots. With power at the high point of green the a/s will be down and that/s reality.

You should be able to get 3 hours of flight time or close to it at max gross weight. At an airport with a running start the aircraft will easily get off the ground. At a helipad or more of a confined area the aircraft will more than likely not jump off the ground. However, be patient, the aircraft will do its job and get off the ground, may not jump off the ground but if you let the rotor system do its job it will do the job. The aircraft is a monster on power.

Noise in the cabin will be based on what type of sound proofing the aircraft has built into it. The more you have on the 155 the quieter the inside of the cabin will be, like most aircraft. Not all 76's air quiet, same with the 155. I have flown a 155 that required no headsets in the cabin and other ones that produced hearing loss with the best of earplugs and headsets/helmets.