I recommend the Zamp Racing Helmets RZ-44C
At around $500 Im confident you couldn't find a better helmet.
The carbon composite structure is lightweight which is a huge plus. This full face helmet is lighter than my old Bell open face Sport Mag. Neck strain is kept to a minimum. The interior material is nice. Not the nicest material I've felt in a helmet but still nice and comfortable. The head shape was a little odd at first but after wearing it a few times and breaking it in it has become very comfortable as well. The helmet does not cause headaches due to odd pressure points as others I have worn. There are plenty of vents in this helmet which promote great airflow. The front and top vents are designed to allow the use of a blower system if you have one. You just need to buy the air adapter. I am a pretty big fan of the way the helmet looks as well. The carbon fiber is clear coated which gives it a nice gloss shine.
All in all I am very happy with this helmet. It has plenty of features that you won't find on other helmets unless you move up the price range. I would highly recommend the RZ-44C to anyone looking for a versatile, lightweight, SA2015 compliant helmet. You will not regret your decision.