As I am a sucker to marketing I have both the Utopia and Utopia Y. Limited discernable differences from the outside, but the internal padding is an improvement. Juries out on the retention system, it seems closer to the head while placing the helmet on, making the manipulation of my he-mane slightly challenging. Also on the retention system, the dial must be super micro-adjust as it feels like it requires quite a few clicks for limited movement. Not really concerns per se, just observations. Still a great helmet, but one shouldn't feel the need to upgrade from the standard Utopia unless said helmet is being pitched.
Very nice fit with good straps and adjustment system. Compared to another high-end helmet I have, it just fits my head better (more snug around the front of the head, whereas the other has a lot of play there). It is an aero road helmet so it does have noticeably fewer vents and looks more rounded/teardrop in shape.
Great helmet for keeping cool and aero. Comfortable sweat bands and rear harness. Light weight.