FamilySearch offers the largest database of free genealogy records on the web, as well as numerous other collections that are available to view digitally at a Family History Center. In fact, many of Ancestry’s indexes are pulled from the original records of FamilySearch. FamilySearch can be searched at no cost and the records viewed by anyone. They also offer an enormous, collaborative family tree and those who use it can take advantage of hints from FamilySearch’s databases.I've never had much use for Ancestry.com. For a start, as a pensioner I just can't afford it, though we did at one time make use of their free Ancestry Lite version called Mundia until it was withdrawn. It gave access to Ancestry public trees, which could be useful, though it was, as this article warns, important to be on your guard, because there are a lot of very inaccurate family trees on Ancestry.
For example, Three Agnes Ellwoods: Tombstone Tuesday | Hayes & Greene family history: we discovered a lot of online family trees for Agnes Ellwood Tallon, on the soon-to-be-closed Mundia site (no links, as they won’t work after September). And every one that we looked at linked to the wrong Agnes!
The Family History Daily site also publishes somewhat misleading information by confusing genealogy programs (which run on your computer and help you to record your genealogy) and genealogy web sites (to which you can upload a copy of your family tree). They do acknowledge that they get paid to write about some of the sites that they write about, but by blurring the distinction between progams and web sites they are confusing a lot of people.
So regardless of what they say, I will maintain that the best online family tree site is FamilySearch. I have grave reservations about Geni.com and MyHeritage -- the latter has some distinctly dubious business practices.
In general, I've found FamilySearch's hints to be both useful and usable. Of course the usual warnings apply -- check and verify them with other sources. And FamilySearch also has the advantage of having a single public tree. Some people seem to get quite upset at the notion of not having "my tree" on a remote public site, as they can do with sites like Ancestry.com, but that is a bit silly, because the place for "my tree" is on my computer, not on a remote site (other than for backup, of course).
The advantage with FamilySearch is that at least two genealogy programs, RootsMagic and Legacy Family Tree, will interact with the family tree, and let you compare your information with that on the public tree, and copy it either way. If there are disputed pieces of information (different dates of birth, for example), you can start a discussion about it, which you can see on your computer, and others can see on theirs, or on the FamilySearch site itself.
In addition, every change that anyone makes is tagged, showing who made it and when. You can put your contact information in the tag (e-mail address etc) so that anyone who has conflicting information or wants to ask more can contact you directly. This is usually much more difficult on the commercial sites -- you have to go through the site to contact others, and you sometimes have to be a paid-up member to do so.
Also, if you find that a hint on FamilySearch isn't useful, or is misleading, you can leave a comment on it, and say why you think it isn't a match, and in that way help other researchers.
Sometimes the people at FamilySearch make "improvements" that don't really improve things, and make the site more difficult to use, but eventually they seem to discover those, and generally it's getting better all the time.