[Erik816]

FamilySearch is excellent and has a ton of primary sources once you get used to how to find them. Ancestry.com's main advantage is that it provides "hints" that suggests sources for your ancestors. It's super easy to add those sources and people to your tree. That's also its main weaknesses, because these sources and hints are sometimes completely wrong, and are then copied and repeated by many genealogists until they take on a veneer of truth through sheer repetition.

[mlinksva]

FamilySearch also provides hints ("research helps") with the same up and downsides. Perhaps this is a recent feature, I've only used the site since early this year.

I feel like there's an opportunity to do automated data quality assessment, and to provide some indication of that in the UI/with the data.

Overall though I'm fairly impressed with the fluidity of the UI and speed of the site, would be curious to know about their backend.