Which Lumia Camera? There's fifty thousand of them and the latest and best version still isn't supported on a huge number of devices. It leads to a jumbled experience where no one really knows what Lumia Camera they should be using.
Additionally, I'm using the device that "launched" Lumia Denim and in extension Lumia Camera 5.0 yet I have to use Lumia Camera Classic.
Let's say 5.0 is what you're talking about. It's basically superior to Microsoft Camera in every way except support. Features, UI, performance, etc. That being said, this could potentially change. There's a good chance (as it just makes sense) that Microsoft will get rid of either Lumia or Microsoft Camera and only have one available. This will likely happen with Windows 10. If Microsoft is smart they'll unify Lumia Camera into one, single app and possibly rename it to Microsoft Camera (if they deem fit). To be frank, I'm no expert on Windows 10 Mobile as it stands right now so there's a chance they've done this already, I don't know. Just my opinions.
Lumia Camera is superior, but it's a cluttered mess. Hopefully Windows 10 Mobile will fix a lot of issues.