Yeah Ricciardi was pretty good at player evaluation at the big league level.
He sold high on Hudson to get Glaus, and later sold high on Glaus to buy low on Rolen (who went on to have WAR's of 2.8, 4.1 and 4.5 through the remainder of his contract as opposed to Glaus who fell off the face of the earth after 2008). He got great value at the catching position seemingly every year (Myers, Zaun, Molina, and even Barajas wasn't terrible). He got Scutaro prior to his breakout. He believed in Rios even though his bat took a couple of years to catch up to his potential. He was able to identify Catalanotto's platoon splits and exploit them. And so on. Heck, one of the criticisms that I remember about his run early in his career was that he didn't value the Gord Ash guys, but if you look at the inherited players that he kept (Wells, Rios, McGowan, League, Johnson, Hudson until Hill was ready, etc) vs. the players he let go (Phelps, Lopez, Gross, Izturis, Lyon, Werth, etc), he was pretty spot on in terms of the players that would end up panning out (except Werth, though it took him a few years to reach his potential).
He wasn't perfect by any means, but I can't recall a MLB move that I can look back on and say "damn what the heck was he thinking?". He was almost cautious to a fault with his trades. Again, it all goes back to the drafting. Tulo over Romero would have helped him greatly, for starters. Striking out on Adams, Purcey, Snider (in hindsight), Cooper, and Jenkins looks pretty darn awful. He may not deserve that much blame for later round picks, but I'm assuming he'd at least have an idea of the first round guys. Outside of Hill, and a couple of Romero seasons, he was terrible in that regard.