i) FLIR makes a wide variety of high-end sensors for both military, commercial, and civilian use. Much of what FLIR seems Mil-Spec in origin. They have a huge market share of high-end yacht business. There other devices aren't toys; and,

ii) The FLIR unit sits in a cradle-like case with the Apple plug unable to wiggle. (It might get filled with rain or a heavy spray, but it wont be bending around while you use the device). The other plug-in looks like it could damage the delicate 30 pin Apple connector on the Iphone -- or at least messing up the device interface itself.

I don't think that I'd be using either device on a rain soaked deck -- but I'd rather have the FLIR unit if I were trying to use the device without having to "baby" the little plug-in imaging device depending on the plug.

I've had enough new Apple 30 pin cables fail -- and they are only sitting around next to bed stand or on a desk. I can't imagine what you'd do when you really bounce that unit around if you were trying to use without being very delicate.

If I were going to buy a device that I would use as a tool on a job site or frequently around the home , to see what's across the water, to check if there was a bear in the woods, or whatever, I'd use FLIR.

There may be some spec differences, I haven't studied the difference in sensitivity, resolution, discrimination, etc. But looking at it: Ask yourself which one you'd cram into your jacket, your pants, your phone holster, or whatever.

A sextant looks more durable.