I guess not accurate as far as temp reading goes, but good image to look around at anything, from wall, ceiling to electronics, people. And be able to see water spot on ceiling that way i would know if there a leak on the roof.
In that case, there will be basically no difference between the TH and non-TH (assuming same lens). The image produced will be the same, just that the TH will have more accurate readings / read higher temperatures.
In fact, if we use the included lenses (ie. the 6.8mm f/1.4 one that comes with the TH and the 19mm f/1.1 that comes with the non-TH), the non-TH will actually generate a dramatically better image due to the larger aperture.
It's far more worthy to spend your money on the 13mm f/1.0 lens ($250) instead of the TH. The f/1.0 aperture will allow in more IR light and actually get you a better picture. In fact, the f/1.4 lens that comes with the TH is a full stop slower than the optional f/1.0 lens, which means
the f/1.0 lens allows in double the light.