Shunter,
Sorry lad, not true.
Honestly, I can't be bothered to argue with such a sweeping statement.... especially when you yourself point out a few limitations in your very own post.
It's NOT a magic plug and play solution.... what worked in your "comprehensive evaluation" might not work for others on their network.
I have seen implementations miserably fail because despite "comprehensive evaluations" by people's IT departments who then go and become over-reliant (no budget shortages, so the "right" models were bought) on it rather than upgrading the WAN as they should have done in the first place and eventually admit defeat and do. Unfortunatley I am not in a position to provide public detail on anything and have no interest in sharing it with you over PM either.
As I said above.... caveat emptor to people considering it. By all means try it, but don't write off the WAN upgrade option, especially given the good deals that can be had these days compared to say a few years ago.