If you are expecting a real live service game with the potential to replay and progress for years, do not buy this game now. It isn't ready yet.
If you want 30 hours of gameplay that can be pretty fun and engaging if you don't encounter the bugs and disconnects others seem to, then you might enjoy the game for a while. Just don't expect to be playing this for years...yet.
Anthem is beautiful, the combat is fun, and it is amazing to fly like Iron Man and explore the world they created. The story will carry you almost to max level and if you take your time will be about 30+ hours of play time.
All of this assumes that by the time you play it, that the thin storyline, the fairly common disconnections and crashes due to bugs, and extremely long load screens have not put you off.
Then you will find your self ready to head on to endgame. This will involve doing the same 4 strongholds, some rather monotonous contract missions, freeplay events, and recycled story missions called Legendary Missions over and over on harder difficulties. This will be fun for a while until you are geared up with all Masterwork Weapons and Gear.
Then it becomes a horrible soul crushing grind as you discover that the Legendary Weapons, Components, and Gear drop only VERY sparingly, and even when they do, you often get repeats rather than upgrades.
Additionally you will discover that the harder difficultly levels that are supposed to reward you with better chances at rare loot, really don't, and there is no reason to run on that level because the return on time spent is not worthwhile.
I could go on, but there really is no need. Anthem, on the face of it is a good game and could be great if they have time and resources to make it so, but I would not spend money on it now unless you are content with the first 30+ hours of game time to be the most fun and then are willing to shelve the game until Bioware pulls something together, of which I am skeptical yet hopeful. I want to keep playing this game, but I can't see the point right now.
UPDATE: With the 1.4.1 patch and the addition of the Cataclysm, Anthem is much more interesting and fun. If they continue to add new content like this on a regular basis, Anthem could reach its potential and really shine.