I went and got fitted at my local store a few weeks ago... this was the recommended helmet, and I did really like it. So, I bought it. Haven't regretted it since.
It's pretty quiet, good airflow. I never feel like I'm suffocating. Good field of view all around. Doesn't get in the way when I turn my head nor is it in any way uncomfortable. Except for when it's just too hot out to wear a helmet in the first place... but I'll deal with being a little too warm any day if it helps to keep my brain in my cranium.
One thing I will note, I've been incredibly careful in my care and handling of this helmet; but I've still somehow managed to get a few knicks in the black matte finish.... which reveals the white shell underneath :( Not a big deal though, I'll just hit it with a sharpie (kidding).
This replaced my RX-7 which was nearing its 5 year life and was showing signs of wear. Have migrated towards higher visibility and hence the fluorescent yellow.
After about 2 months of wear, I must say I'm pleased. The comfort and build quality of the Arai is unchanged, but I believe this is noticably quieter than may RX-7. Did a run from so-cal to Laguna Seca and forgot to use my earplugs on the way home and didnt really suffer as a result.
As for the other new features, well, visibility? Maybe better. The emergency removal? Haven't tested.
What I was most concerned about was ventilation. The RX-7 has three front and two rear vents. The RX-Q has two front and one (control) for the rear vents. While the configuration is supposed to be better for street than the RX-7 (designed for the trak) I cant say I noticed a significant difference good or bad. BTW, my ride is a '04 Honda VFR with Heli-bars and a Zero Gravity double-bubble windscreen - a sport touring setup.
It's an Arai...no more needs to be said really. Quality speaks for itself. The fit is always spot on. I'm 56 cm around with an intermediate oval head and always fit a Small in their helmets. Except for their Signet Q which is very long oval in shape.