Q: Will this marker be upgrade able with etrigger, response trigger, or cyclone feed?
A: It will not accept any current etriggers, response triggers, or cyclone feeds. Oct '13

Q: Can I add different stocks other than the Cronus stock?
A: Yes, the Alpha Black compatible stocks work. The Cronus has a stock adapter the same as the Alpha Black.

Q: My question is how light will this gun be. I want to buy one with the tactical package and field it, and that will be so sweet!
A: The Alpha Black (with no stock, but including fore shroud) weighs 4 pound 2 ounces. The Cronus with no stock or shroud weights 2 pounds 12 ounces. Much lighter.