Jack is a top 10 prospect so you have to consider him but I think the fact that there are so many 1st round caliber guys left on the board (Robinson, Dodd, Reed, Ogbah, Billings) that are clean off the field/in terms of their health makes it difficult to pick him at 34.
If we were at 45 and most of those guys were gone I'd be much more about it, and even as it stands I'd be happy with the pick, it's just a roll of the dice when you have other very good prospects available who don't come with as much risk.