At the firm that I work at everything is in the open, even between groups, and it works very well. It is a formula-based compensation given your department (basically consultants and back-office) and stated level. With that, I know or can calculate exactly how much my manager makes, how much an entry level HR employee makes, and how much the CEO makes.

I love it because it removes any problem with politics or shadowy discussions, and I know what I can expect when a promotion comes. The only downside is that it leaves the firm with little leverage when it comes to compensation: I can't simply get a bump without a promotion, nor are there extra bonuses that can be given out either for hiring or retaining. (This has its benefits as well however.)