Like many, I'm not a pro using a thermal imaging camera on a daily basis, but I'm still a geek who enjoys these tools/toys. I've wanted one for a long time, and the Flir E4, priced at just under a thousand, is finally within reach. I've had it for almost a week now and it's like I see the world in a completely different light (literally!). The main "hands on" use for me so far has been finding areas around the house with insufficient insulation - spots in the attic (especially around the edges of the house), air ducts and vents, uninsulated garage doors, etc. This is very insightful and let's just say I'm sure I'll be adding insulation soon from what I've seen here! In addition to insulation, there are of course many other possible uses. I'm sure you can think of more than I could ever attempt to list here. When aiming, keep in mind that it is quite sensitive. Depending on the temperature range under consideration, the automatic temperature scale often exaggerates small temperature differences, which can make a hot/cold airflow or leak, for example, appear worse than it really is. It's very nice to see tiny temperature differences; you just have to be aware of what you see. Please note that the temperature scale can be locked. Also, I think that when photographed, the entire range is saved, so in the downloadable Flir software you can adjust the displayed temperature range regardless of how it was set when the photograph was taken. Purchased July 29, 2014 from Revain, ended up with an "E4 1.1L" with firmware 1.22.0. By the way, even without the software improvements, E4 is still incredibly interesting and useful. Whatever the thermal resolution, the MSX feature is an excellent concept that makes what you see clearer, provided of course that the surrounding (visible light) is bright enough.