I tried the Carson microscope. The problem I had is that I found it difficult (near impossible) to keep trichs in focus unless I cut parts off the plant and put them on a support in order to look at them. The microscope is fine, but using it on growing plants did not work worth a damn for me. I also tried a loupe, and it was slightly better because at least with the loupe, the image moves in the direction you expect, whereas with the Carson, you need to learn to move it the opposite direction you think in order to look at a different part of the plant. It was almost impossible to tell where to move with the Carson due to the direction reversal and the fact that the area of view was seriously tiny.
In the end, I gave up with the microscope entirely, and although the loupe was slightly better for me, I found that my best option was a macro lens on a digital camera. I already had the camera, and bought the lens for the purpose. I found that by taking careful photos, using a tripod, and enlarging them, I got the best view of trichomes from any of the options I tried.
Bottom line is that both the Carson and a loupe will do the job, but neither were the option that worked best for me. If I had to choose between the two, I would go with a loupe like the one I got:
Amazon product
I didn't try the usb microsope, but had the macro lens not done the job, I would have gone with one of them. To get the best results with one, you might need to put it on a tripod to steady it.
Good luck with your decision, and happy growing.
