Hi monotonic, interesting that you would ask as I recently got one of these, though a smaller one as they are cheaper. I don't think they're FIR, just infrared. I used to own a FIR lamp, but it broke down after three years, and get-fitt.com stopped selling them. I'd personally say that FIR probably has a better effect than infrared (based on my experiences), but so far the infrared lamp doesn't seem to be too bad either. It seems to have a positive effect on my skin/eyes. If you're tight on budget, perhaps an infrared lamp would be better, if not then I think the FIR blanket would be the better option. If you do take an infrared lamp, be careful not to keep it too close (I keep the distance at min. 80 cm), I also make sure to have my eyes closed.
There's also this Sott.net podcast about FIR: https://www.youtube.com/watch?v=4BiuYPo30Eg
Hope this helps!