I'm curious...what differentiates them? I believe the Naza Lite came in my Phantom I and II. Now, just for fun, I checked online and found some current prices.The Naza M Lite with GPS can be had for $169. The Wookong is $999 (including GPS). The Naza M Version II is $299 (with GPS and compass). Finally, the A2 is $1,300.00. Obviously lots of capabilities in some, not so much in others. I'm not out to buy any of these today since my quad bank account is depleted at present, but wanted some feedback from others that have used any of these. Why one over another?