I am a Space Sim fanatic. I own and strongly support both Star Citizen as well as Elite Dangerous. But, I confess that while Elite Dangerous has come out onto the gaming scene first, the greatest potential lies in Chris Robert's Star Citizen.
First off is the fact that while Elite Dangerous has beautiful content and graphics, it is overwhelmingly anemic to lore content. Frontier has only begun entering the rudiments of lore only recently, while CIG is using lore as a major foundation. Most people playing these games are role players, and if they cannot fit themselves into a game, then all the cool graphics and game mechanics will be of no avail. The developers of Star Citizen know this, which is why the lore and backstory is being heavily developed even before the game is out.
Second reason why Star Citizen is lead the pack is because the ships are not limited. In Elite Dangerous, a major event is docking in a station. Ever since I played Elite back in 1984, the process of docking was always limited heavily by the entrance to the station. This gateway is a MAJOR HINDRANCE to space ship design in the game. While at once time, it was a challenge, and an element for nostalgia for the older payers, this same entrance design is a horrendous obstacle, handicapping ship design in the game.
Granted, it is my opinion that the game Elite Dangerous will be the closest contender to Star Citizen, David Braben's awesome game will continue to be 2nd Best, until these two obstacles are resolved.