We played our first game (4-player) with the Fishermen addition.
Our overall impression when it was done was that it did the following things:
1. It sped the game up a little bit. Having the fish to buy resources and roads was a great help, but it would definitely depend on the rest of the board, too. Just having an extra resource to spend.. that helped.
2. It made the non-port coastline appealing! We saw people building where they otherwise wouldn't have, and even a couple people starting with buildings on ports/fisheries.
3. It depends on who you play with. We didn't see anyone spending 3 to steal, when 4 would buy anything from the bank... but I think some groups might be more aggressive with the fish. Also, it might be a nice way to stop someone from winning on their turn, if you steal a bunch from them before they go.
4. 7 fish for a development card is good, but... holding on until you get that many fish could take a bit of doing.
5. The shoe isn't the end of the world, but it does stop a single player from running away with the game. You can get rid of it and win in the same turn if people are close to your totals.
All in all, we think the addition is nice for a change of pace. The number seem pretty balanced, and the shoe did play a role in the game (albeit a small one).
I highly recommend this to any Catan fans!
J