Legitimate concerns have been done to death, ultimately it comes down to how much stock you put into them.
His lack of experience is a legitimate concern. Only a few years actively managing. That said, everyone needs to start somewhere, and if AVB is to be as good as some think then now is the time to go for him - otherwise he will be out of our league before long.
His insistence on a high defensive line at Chelsea, despite it not working. Concerns me a lot. I consider that we have players more able to implement his preferred system, so that in itself isnt an issue - but his insistence on stubbornly using it despite it not working at Chelsea worries me. I can only hope its something he has learnt from.
His "players must celebrate with me" and break down of relations with the media concern me. It shows that he got sucked into the situation instead of managing it. In some ways I think its tied into his commitment to the role, he seems to take it very personally and have a near obsessive desire to do the job thoroughly - a commendable value - but he took it to far here. Again, I think the players are less likely than those at Chelsea to create this situation so Im less inclined to worry about it, but the fact it happened concerns me. Once again I can only hope he has learnt from this as well.
Reading up on his time at both Academia and Porto it is clear he was able to build a very good relationship with the squad, so at present Chelsea is the exception more than the rule.
AVB isnt perfect, thats for sure.
He does, however, have a lot of very positive attributes I believe to be in line with what this team needs to take it forward. I also think he is well suited to the club.
Any managerial appointment is a risk, its about weighing the positives against the negatives.
For me AVB comes out as a positive over all.