I think I would trust the LDS websites more than any of the other sites. From what I hear some of the others sell their DNA data. What if they sell that information to insurance companies?
I have had good experiences with the LDS genealogy people. They have offices all around the country with people who really know genealogy. You can make an appointment and they have access to a lot of records. And it’s free.
I guess the only thing that would prompt me to get any DNA testing done is if anyone in my family and/or I had a mysterious illness — just to identify genetic issues. Also, searching for missing relatives would be another reason. Otherwise, I’m not wanting that info “out there” for any reason.
I’d assume that there may be employees at these non-medical agencies who may not be totally on the up-and-up. I’d hate to have a sample of my DNA available if someone wanted to pull something nefarious. I know; I watch too much Investigation Discovery Channel. :) And then there’s Uncle Sam, who I wouldn’t want to assist in having the info — although I figure they could get it now if they wanted it.
Wanting to get genealogy info just for kicks ... I dunno. It might not be worth the risk.
But LDS combines their records in absurd ways. If you want to imagine this poor woman having 39 children, ... I tend to use LDS carefully and edit what they say. The big thing I look for are exact dates rather than abts. Then you’ve got a chance that they’ve collected good data. The new websites that copy off tombstones are a big help, too. Though, there, too, the data on the tombstones can be wrong. My new favorite data source are the newspaper archives. Actually reading the names in the old articles is fascinating.