I use Luna Display every single day as an interface for a headless Mac server I have in my setup. Works flawlessly with recent updates.
If I had one major complaint/wish it would be for Luna to utilize the built in keyboard function in IOS. Having to peck out characters on the remote Mac using Mac OS keyboard viewer is frustrating to say the least and really takes away from the experience. Ive read that the only workaround is to purchase their Astropad software which seems like overkill to obtain this functionality and sort of smells of a money grab?