I have both a GT-Air and a Neotec II, and while I would buy another GT-Air, I regret the Neotec II purchase. The Sena SRL is the only comms device you can really fit to the Neotec II, and it's a poorly designed system that makes too many functional compromises in the name of appearances. The buttons on the SRL were designed for form before function, and are the worst UI Sena has created for a comms system.
The Neotec II is also a much louder helmet than the GT-Air, the modular hinge being responsible for the difference. I can comfortably wear the GT-Air without earplugs for anything but a full day of highway riding. Neotec II, earplugs are a requirement for anything more than a quick trip to the store. On the other hand, the utility of a modular helmet is hard to do without, once you've experienced it.
Both are very well made helmets. Both would be better if they had a visor notch that was about 3mm above full closed. Shoei has known about that complaint for years, they don't appear to be in a hurry to fix it. I guess if you want a helmet that can vent via the visor, you just buy another brand.