Yes, I typically do open downloaded models and look them over before using them. If for no other reason, to change the units to inches. (I love the metric system, and would choose to use it if it weren’t for all the other people involved in the project!)
I recently downloaded a desk with an office chair. A quick look didn’t show problems. But when I placed it in my model, strange things began to happen. I turned the model over, and the wheels of the chair were all sticking out the bottom!