As a product owner who uses LaunchDarkly, my preference is to always abstract complexity if its not core to my product. I am always an advocate for tools and services that allow me to get to market quicker, while reducing long-term overhead. An internal service like LD would need to be built and also maintained. I think many people overestimate the complexity of services like this; it seems simple but execution is always more difficult (scale, bugs, features, etc). Cheers to LD for providing this service so my team can concentrate on our core.

We use LD, because (1) we don't have time to make a pretty UI with user management and audit logs, and (2) we like the reliability story of running all of the heavy lifting through fastly's CDN.

They are a little more pricey than we'd prefer, but we're happy.

You might be interested in this comment by @DannyDouglass linking to a case study and their implementation -

https://news.ycombinator.com/item?id=13231518

I've used it. I wasn't super impressed with the features around grouping accounts so that you can match a group with a feature toggle. As I recall, it was mostly regexes, rather then a long running group system. I'm guessing a big infusion of money will help with this.