A very thin FA class just got thinner today when Neil Walker and Jeremy Hellickson accepted their QO's from the Mets and Phillies respectively. These are probably good deals for both sides as the players like will get a significantly higher single season salary than they would from a multiyear deal on the open market while the teams probably will pay a bit more for equal talent in a single season, but avoids the risk of a multi-year commitment. Of course, there is risk to the players that a severe injury could cause their future value to evaporate, but chances are that a series of single season contracts will outperform a single multi-season contract of the same length. I actually do not understand why more players don't take the single season QO.
Among players declining QO's and becoming FA's are Kenley Jansen, Mark Trumbo, Edwin Encarnacion, Jose Bautista, Justin Turner, Ian Desmond and Dexter Fowler. Sought after relievers Aroldis Chapman and Mark Melancon are exempt from QO's having been traded to their current teams within season.