I believe there is not one light that is best for every situation and IMO it's best to use 2-3 for inspecting. That being said, I prefer my Fenix PD35 and TK15 for inspecting my work over all others. I'll also use my LED headlamp on jobs where 99-100% correction is the goal.
The sun definitely does not show everything and there have been numerous time where the Fenix shows micro marring that can't be seen under the sun. It's also not always available which is a huge factor. I do feel it is good for seeing rotary holograms though. I was not impressed with the Sun Gun.