I'd be nervous NOT to be in right now.
I think it's prudent to be nervous on both sides of this bet right now. It's always been a risky play.
I think the decision comes down to "1- does this technology work? 2- Will it survive attack?"
If you believe both of these questions resolve to yes, then the potential returns on investment should outweigh the risk.
If you have doubts? Then your risk assessment might not allow for such a speculative play.
Personally, I think there is a significant risk of attack from within. There exists an attack vector where one person or one group becomes the incumbent contributor to the bitcoin code. If changes are not sufficiently challenged and vetted there exists a real threat that someone could be coerced to add some seemingly innocuous code (expand the blocksize to 200 MB perhaps?) Which would effectively kill the bitcoin protocol as a censorship resistant form of transferring value.
That being said, there is a group which concentrates on purifying the code and removing unnecessary cruft from the code base. Luckily, because of the nature of the consensus mechanism, it is unlikely that any change will be allowed to happen absent the approval of said group.
