SE V2 improved the tail box, added thrust bearings to the blade grips, extended the battery plate, improved the one way bearing and main gear, came up with a new decal scheme, improved tail drive pulley and changed the anodized blue metal to a slightly darker tint. SE V1 doesn't have the new features (of course) but has the carbon fiber frames, anodized aluminum parts and all kinds of other goodies. If I missed anything, someone chime in.