Are you looking at that X50 on eBay? It isn't really an X50, I know because I returned it. Seller originally had it advertised as an X150 (which it isn't). I think it is an X100. Either way, it is definitely a Raytheon built MX-1 (and I believe it has a a 30hz refresh). I made the guy an offer for $1250 and returned it. It works, but there are some scratches on the viewing lens and it caused some pretty bad blooms when looking through the viewing window. I also wanted it for the 1/4-20 threaded hole for a tripod mount (which it didn't have).
I can confirm that the unit works. I was able to look up and down my street, and outside in a wooded environment and I think this unit would serve perfectly for an observation post type device. However, if your intent was use it while walking around - forget it. It freezes the display every 30 seconds for .5 seconds.
For $1250, I'd rather buy another Pinnacle Tube PVS-7.
My gripes:
Image wasn't very clear.
Everything blended together/washed out indoors.
I hid hot/warm items under my car and behind some bushes to see if I could discern shapes - I had trouble. Under my car, the entire underside was glowing.
I tried tracking footsteps, engine bays, cold/hot drinks, etc. I just wasn't overly impressed with this device. I can't speak to the FLIR, but I've read that the Thermal Eye is a pretty decent devise. I was largely unimpressed.