@BillRM,
There may be self proclaimed experts, however, you are missing the point. Not really surprising. We have heard plenty from outside experts in many different sides, some from civil rights lawyers and some from those you focus on. What we can not hear from to any useful degree in order to contribute to the public debate of national security is from those who work in national security now because of their oaths to secrecy and because everything is classified. The author of the article is saying, the end result may be we end up with legal programs that won't work as good as the one we end up discarding.
What they should do, in my humble opinion for what it's worth, is to just concentrate on what is most efficient both in terms of cost and end result and then hassle it out on trying to make it legal. From what I have been reading, most think dragnet surveillance is not very efficient in either direction and should be discontinued on that basis alone and it would also make a lot of the privacy side happy in the process so a win win situation.