LANC is over rated. I have it and it never gets used. zooming on the heli is no different than zooming on the ground, it makes for a cheap looking shot. Hit record on the ground and you know its on. Maybe for surveillance or inspection it could be handy. As for resolution, thats not going to show up. The resolution is like horsepower on a car, it's all marketing. As for glass, that could make a difference but not the kind you and me would be able to tell without painstakingly comparing them. Look at the gh2/gh3 comparisons. You have to make yourself think you see big differences to justify buying the new. It's possible it is soft or has some vignetting but it's unlikely. Truthfully, the only reason to buy this camera is for the BOSS and if it is half the cost and has a BETTER BOSS??? buy it!
the stock lens on the 5n is not all that great compared to a top of the line lens but it is very good nonetheless. I would say the video cameras have pretty good optics in them as they are since they are not interchangeable.