Oh yeah the customer is paying so the cheaper rate is always best. My company has thousands of guys in hotels nightly, so our rate won't be impacted so the few times I use the other companies rate, no biggie and we all win. Example my company is $449 in DC this week and the other guy rate is $229 so I used the other guy rate. Next week our rate in DC is cheaper so I will use our code.

I could see where this could be an issue with smaller companies where Marriott might send reports to the travel teams where I was in hotels 200 nights but only used our rate 100 nights. But we're a monster organization so it won't matter.