Its not bad, but it could be much better
Anyway, the game itself isn't bad. I've had it for a long time and its the kind of game that you play, get bored of and them come back to a few months later (what I did). The fact that each faction has the same basic troops is a bit boring but at the end of the day each faction does have their own unique troops e.g. King Arthur has his Knights and Merlin.
I don't think the factions are balanced very well. The "Good" side (King Arthur and his Knights) are definitely the most powerful and its easy to take a castle with just a few knights. The ice faction have some ok troops such has giants and witches, these can be annoying but are no match for a few archers and knights. Then theres the evil side, they have things like werewolves and giant bats but they have nothing that makes it easy to take a castle. I think that the developers should have spent a bit longer on it.The story missions are kind of boring but I never do them all at once. One thing I do like is the "Legends Trails". Basically its a set of ready made skirmishes that gradually get harder. Its satisfying trying to complete them all. You can find games with better graphics elsewhere but thats not saying that the graphics on this game are really bad, I've seen far worse.
This game is not perfect by a long way, but its not terrible either and if you like playing strategy games you should definitely try this.
EDIT: I decided to play Stronghold 2 again and this caused me to lower my score from 6.5 to 5.5. Legends gets rid of so much of the stuff that I love in the previous games. The magical aspect of Stronghold Legends now seems kind of stupid, it makes the game far too easy. Instead of having to use ladders and catapults to take a castle, just smash their castle down with a few giants, or use King Arthur's knights to destroy them. The economic side of Legends is also far simpler. Its still an enjoyable game but to me it feels like a dumbed down version of the previous games.