(PLEASE NOTE ALL SCREENSHOTS ARE FROM MY ALT ACCOUNT AND THEREFORE EARLY IN THE GAME)
SAO's Legends is a very interesting game (great start I know). Seriously though, that would be the best word to use - flawed. This is derived from a few obvious issues. These include the auto-battle/auto-roam features, the amount of random items the game bombards you with at the start, and the lack of individuality between players.
The auto-battle and auto-roam features cause the playable character to instantly rush towards the current quest/objective fighting any necessary battles along the way. However, this can make the game feel almost like you are watching a speed-run video of someone else playing the game.
The random items I was overwhelmed with at the start was too much. I don't know/care for what half the stuff did and yet I was just given it to me. This happened at the end of every quest (which at the start is a LOT).
When entering the game world, you are presented with a choice of class. The warrior, ranger, priest and knight. This choice essentially determines your look and skill for the game. Unless I missed something crucial, you will look the same for the entire game. This isn't necessarily a bad thing, except for the fact that depending on who you choose determines your look (Warrior - Kirito, Ranger - Sinon, Priest - Leafa, Knight - the evil guy from season 1 arc 1). This creates a sense of no individuality between the players due to everyone looking like the same 4 identical characters.
While the game is not necessarily bad, it comes with many obvious shortcomings. In the worst situations, these shortcomings can prevent a sense of enjoyment from being derived from the game. Let me quickly state, this game can be fun - but not all the time. Other times it feels a little tedious going endlessly from quest to quest.
If I could rename it, I'd call it Flawed Legends
Although it is flawed, I found that the world/art, music and voice clips were rather pleasant. All areas of the game seemed very unique ranging from temple like structures, to forest areas. These areas gave a sense of progression which other aspects could not provide as getting to different higher level areas means you yourself are higher levelled. Each enemy was also fun to fight against (with the favourite being the Drunk Ape).
The voice clips are the original voices presumably derived from the anime. The music was another aspect which stood out. The music made me constantly feel like I was on a mission (which I was), that I had somewhere to be, something to do. I like it :)
In conclusion, I would definitely recommend giving SAO Legend's a go, but don't go in with high hopes. However, if you are a fan of games like Naruto Online, then this game might be for you.