From what i recall, they traded 2 mid round picks for Ochocinco. There was a lot of hype with the Chad Johnson trade too(not too dissimilar to Cooks right now) and he was being drafted consistently in the 4th and 5th rounds, he was a monumental bust. The expectations were very high with him too, that playing with a great QB and coach will be really good. But it didnt pan out at all. Mind you, it was a completely different story with Randy Moss who also ended being drafted around 4th/5th and returned top 3 value in most leagues.
I know I love belichick alot but he has had failed trades, specially in the last 5-6 years.
I will probably take the dive on Cooks late 2nd/3rd(cant ignore the potential upside) but i feel Cooks was better off with the Saints overall. Saints offense was way more fantasy friendly as a whole (except for the RBs).