Yes, I agree, the expansion does change the game so there isn't that repetitiveness issue. Before I got the expansion, I pretty much played the same strategy every time. With the expansion, it changes it up enough so I have a different strategy each time. The five elements of the expansion are the Destiny cards, Governor cards, expanded province mat, replacement rows for the province mat, and the soldier tokens.
In the base game, there are no Governor cards. The Governor cards are nice because some can be pretty powerful. One of my favorites is the Duke, which allows you to move your dice from the highest spot on the board to the Duchess. Of course, you can only move there if the Duchess hasn't been taken by another player. The Duchess is my second favorite spot on the board (the queen being first). So with roles like that, sometimes players will purposely take those spots so you don't benefit from them. The nice thing about the Duchess is that you get any two resources of your choice and a plus two token. So thwarting a player who is playing the role of the Duke for the game can become more of a strategy for the other players.
Also, the nice thing about the expansion is that you have a province mat of seven rows instead of five. So there are more options on what you can build, changing that aspect of the game. In the base game, I usually would build the same buildings game after game. My strategy for buildings really didn't change. However, with the seven province mat, that changes it a bit. Also, there are replacement rows for the province mat. At the start of the game, you randomly draw two replacement rows, and have the choice of replacing one, none, or both of those rows on your province mat. So you can have different combinations of buildings each game, thus possibly changing your building strategy.
The Destiny cards are drawn at the beginning of each year (round). They can have various effects, that affect that year only. The effect can be neutral, positive, or even detrimental. The effect of the Destiny card applies to all players. Some of the effects they can have include things such as changing what advisors can be influenced or make players pay certain resources at the end of that year or suffer consequences, etc. For instance, there is a card called The King is Sick, which when drawn, keeps the King from being influenced for that year. And if this card in drawn a second time, the King dies and the game immediately ends.
The last part of the expansion is the Soldier tokens. Rather than rolling a white die and adding that many troops as reinforcements for all players, each player secretly chooses one of their numbered Soldier tokens and then reveals it to all players at the time of the battle. The number on that token indicates how many additional troops that player gets. So in this case, there is less chance involved by doing it this way. At the end of the game, the leftover token(s) count as victory points. This can possibly mean the difference between winning or losing if its a very close game. One thing to note, is that if the King dies and you have extra Soldier tokens, they ALL are counted as victory points. Normally, at the end of year 5, when the game normally ends, you would only have one Soldier token to count. But if the King dies, the game could possibly end after only two years, leaving you with four Soldier tokens. This situation actually came up a few nights ago at my game group. We drew a second The King is Sick card at the beginning of year 5, which ended the game a round early. At that point, I was one point ahead and with the totals of the two Soldier tokens, I tied with the player who was in second place. At the time, there was no clarification in the rule book regarding what you would do in this situation (whether you counted all tokens or not), but it is clarified on the BGG forums.
Basically, with the expansion, it makes Kingsburg more of a gamers game than a gateway game. The expansion is definitely worth buying. If you like just the base game of Kingsburg, you'll definitely like it even more with the To Forge a Realm expansion.