looks like a good concept to my mind. Interesting article and great to see the scale demonstrator actually flying.
The things that spring to my mind are failure modes. Whilst someone has already brought up a total loss of power in the transition to forward flight, which would be an area of concern, what about the tilt actuators failing in the forward flight configuration? I would imagine that would make the landing somewhat tasty? (As an aside, how does the osprey deal with a landing in "plane" mode?)
Also, whilst you say the aircraft has a fairly good lift/drag ratio, how well do you think it will glide in the forward flight configuration with the proprotor dangling out the front?
Anyhow, best of luck with the project, early day, but I hope someone provides the cash to look at it further, as it looks interesting!