Rotorrookie
I would say from a maintenance aspect that the 350 is a easier machine to work on than the Bell. That being said the success of operation depends alot on who is doing the maintenance. If your mechanics are EC guys then they could probably work on the 407 without too much trouble. If they are Bell guys then converting to the 350 may not go so smooth. Bell has very good manuals for the most part and EC and Turbomeca have a much different approach that many people find hard to learn. With a good wrench on staff the 350 is a pretty reliable aircraft and doesn't require a huge amount of tech support from the manufacturer. The 407 may be a bit easier for the new mechanic to learn and what he doesn't know he can usually get help with from Bell fairly easily, not always so with the EC/TM product. Beware also that tech support varies widely by region with every manufacturer so just because someone has great support from Bell in Dallas Tx doesn't mean you will where you are! The same goes for the bad reputation for EC and TM support
Experience really is the key. The maintenance manuals today are written to keep the manufacturer from getting sued not just to tell you how to work on the machine. There are lots of things that are not written in the books and it isn't easy to just "tell you all the tricks". It takes some time for someone to learn all the quirks of a new aircraft and know how to keep it flying in a cost effective manner and find things before they become an AOG situation.
350boy,
The B3 is one with the Arriel 2B engine which is a single channel FADEC and a mechanical backup system. The B3+ as it is sometimes refered to is a 350 with the Arriel 2B1 engine which is a dual channel FADEC and an electrical backup system directly out of the EC130B4. No real power differences to speak of but most folks like the dual channel set up a bit better.
Hope it helps
Max