I've used it quite a bit and I've also corrected some things where I could. It doesn't take long to realise the dead ends and mistakes.
It also opens doors but you have to actually open every door to see what's behind each one. Even doors you wouldn't consider and places you wouldn't think to look.

I've been lucky in that I've found others doing the same research within a family or individual that I was also looking at. Those were the best finds of all, for the ones on my own took forever.
I find history is sometimes more interesting than the present and more understandable than the future.