I was looking for tear-down videos of the HT-19 and unexpectedly found out that HTI was putting out a new version of the HT-18 and HT-19. The new ones can record video and export radiometric/visible composite image data now, which are quite nice considering that HTI is selling these at the same price as before.
The video recording function is interesting, but with only 3 GB of internal memory I'm not sure how long individual videos will be limited to. No video of this function is available yet, which is a shame. Based on the demonstration of the image analysis software, it looked like somehow both visible and infrared data are stored in the same jpg.
For the time being the new version is only available through the manufacturer's website. That said, it looked like the change is purely in software as the specifications were the same. I sent HTI an email asking whether or not existing units can be upgraded and will post an update when they responded.
Update: They said no.