Dont get me wrong he is a very good prospect and would adress our biggest need as far as prospects go. I like him as a player but nothing is guaranteed with young dmen. Look at Gudbranson, Bogosian, and even Schenn. All these dmen looked like the real deal when they first came into the league and all are bottom pairing dmen now.
Garland is a bird in the hand, signed long term through the prime of his career. That's why I would want a sweetener. Moot point though, knowing new York they would want the bigger fish in Miller.