I still have my current town, since December 25th 2013. I was inactive on the game for the second half of 2014 pretty much and I was considering restarting when I came back but decided against it when I did come back
I have both in my town, both have advantages.
The police station sometimes has random items sitting on tables inside which you can take, but other than that there's not too much that's special about it.
With the dream suite, not only can you visit other players towns, but you can get 5000...
You don't get a code, but if your eShop account is linked to your Club Nintendo account a survey will appear in your Club Nintendo account shortly after downloading it.
Since Pokemon ORAS was released before the announcement of Club Nintendo's closure, you can still get coins. :)