I run an EN480B and agree that, for many private pilots, it's the perfect helicopter - safe, secure (especially when windy), easy to fly, spacious, comfortable - and, of course, that lovely RR turbine.
But, for shared ownership, I would start with one co-owner and then gradually add others, one at a time if necessary. The priority is that all the owners share the same philosophy towards maintaining the helicopter, taking perfect care of it, and dealing with the inevitable expenditure.