In all fairness, I can't really compare this to the mayor expansion, because I have only played it once.... but I've used the others many times, and so far this one is my favorite. It does have a "commodities" element which I first feared would make it too much like resources in Settlers, but it is totally different.

My husband and I really enjoy this game because it is fun and two can play. We can also have friends over and have the same amount of fun. Great game!

This is a good expansion for Carcassonne (you *cannot* play this as a stand-alone game, you *must* have Carcassonne already!)

Each color (including gray) gets two new meeples, a "pig" and a "builder". The pig is added to a farm for +1 point for every city (regardless of whether you're playing with the new rules or the old ones). The builder is added to a city or road that you already possess, and allows you to take an extra turn (no more than one extra turn-per-turn) every time you add a tile to said city or road. (Oh, it's great fun to close somebody's city for them right after they added their builder, thus robbing them of their chance to get their extra turn!)

There also are many cities with 'trade goods' in them - cloth, wine, or grain. The person who completes a city with trade goods in them - not necessarily the person who owns that city - gets the goods. At the end of the game, the person with the most in each good gets extra points. Oh, is it ever fun to close somebody's city and get a sweet, sweet reward!

This addition to the standard Carcassone game is my favourite of the ones I have tried so far. The trading pieces make it worth while to finish other peoples towns or try to gazzump them for the extra points. Good fun.

I've only used the Traders & Builders and Inns & Cathedrals expansions, but I've also Carcassone the City and Carcassone without expansions. OF the four variations I've played, Carcassone with Traders and Builders was definitely the most interesting.

The variations on the game have already been described well by other reviewers, so I'll limit my comments to what makes the expansion so interesting:
-the trade goods give players an incentive to complete other players' cities; in other versions of the game, players often avoid other players's cities because they don't want to expand the city (adding to the city's value) of close the city (causing the city to be scored).
-in addition ot being a fun twist, the builder is also a great way of speading up the game. I think it actually took us less time to play with this expansion despite learning new rules and adding tiles.

If you own Carcassone, you should own this expansion.