Haven't really seen it come up, except in my group's current pathfinder campaign. One of the party members recently switched to playing a Paladin of the church of Murlynd. (Specifically a Paladin 5/Gunslinger 1, in our GM's campaign, firearms are a closely kept secret of the church.)
Even then the paladin's code has only come up once since he started playing that character:
Last week we were hired by a local shopkeeper to put a stop to this gang that had been shaking down local businesses for protection money. In addition, we found out the town guard had a bounty on the gang--but it was only payable if we brought them in alive.
After tracking down the gangs' hideout and having my character scout the location, the psion and I worked out a great plan:
The psion has an ability that lets him create a large quantity of any organic substance--including alcohol and organic poisons. My character (an emissary of Cayden Cailean) would buy a wagon and some barrels, and bring it to the part of town where the gang's hideout was. The psion would hide in the back and use his power to keep the barrels filled with conjured beer, which we would then pass out for free as part of a "community outreach program" on behalf of my church.
Once we identified the gang members in the crowd, my character would challenge them all to a drinking contest, at which point the psion (still hidden in the back of the wagon) would conjure up a barrel-full of booze spiked with poison for the bandits, and a barrel of alcohol-free beer for me. I would then proceed to drink them all under the table (with help from massive doses of wisdom-damaging poison) after which we would tie the gang members up and drop them off at the local prefect's station.
Everyone loved the plan, even our GM...
...and then the Paladin started whining.
30 minutes later, we finally shut him up by pointing out that we hadn't actually
told his character about the plan--it was just something my character and the psion had been discussing together. Honestly, I think his only problem with it was that we were going to bypass the combat and he (the player) wanted to bust heads.
In the end, it worked out great. My halfling emissary/scout drank the entire gang of humans into a stupor except one who nat 20's his save against 15 doses of poison. The two of us kept going for another minute until I flubbed a fort save to hold down all the liquid I'd been drinking, and as he raised his arms in victory the next batch of poison kicked in, and he failed his save and fell over.
The rest of the party took the wagon down the street to lead the crowd away, and the Paladin and I ended up taking down the gang's leader by ourselves when he came out to check on his guys.
I am now a legend in that part of town.