I've had extended family do it. I haven't, don't think my dad will any time soon.
There are some .... concerns I have with it, and I frankly don't think the information provided is worth the concerns at this time. That may change in the future.
First off, the information provided is not really accurate as it's advertised. The services don't have a pool of ancient DNA to compare to, all they have is current DNA (hey, submitted by you and other people like you!). So what they're doing is comparing your markers against people living in regions presently, and hoping that migration was limited enough that this is a ballpark estimate of where you came from. I think that's probably close enough for government work at the high percentages. But really, when you're looking at "5% from Ghana" (or whatever) .... they're probably just picking up the Europeans who moved there in more recent times....
That being said, the item that is of interest, which opel hints at, can be finding relatives you don't know you had.... that's also the feature which the police can use to find any of your relatives who may be criminals... There was one case already where the police submitted DNA evidence to one of these private companies, pretending to be the person (or this is how I recall the news story went, I could be wrong), and when the company came back with "You have a cousin in XXX named Dstieger", they went and reached out to him... asked him if he had any cousins he knew of in whatever city the crimes occurred in.... and he fingered his cousin (.... not that way.... or maybe that way... no judgement).
Then, finally, is the irritating part that you are part of the product. Just like Facebook... but with facebook you aren't paying to be part of the product. With these DNA sites, they couldn't exist or work without your DNA submissions. Your information becomes part of the database they compare people to. But you aren't getting compensated for being a product. In fact, you're paying for the privilege of being the product. I know intellectually that there is more to it, they have created an infrastructure into which your information can be searched and matched etc etc... but I'm not thrilled to pay someone to allow them to then use my DNA to make more money, while opening the door to entities searching my DNA... who knows what other companies may choose to do this....
So I'm a meh