I find Octalink is not as smooth as the Hollowtech. Or as smooth as my Campy Record BB (cups & cones). But I have a rather inexpensive version of the Octalink. They work fine, but may wear out rather quickly - depending how much, and where, you ride. But that doesn't present much of a problem as replacements are cheap and available. And installation is a 5 minute job - assuming you have the proper tools. They are specific tools for working on BB's and can't really be fudged together out of what you have in your tool-drawer. So you can either invest in some tools (and learn how to use them), or take it to your LBS to do for you. It's, as I said, a 5-minute job. So it shouldn't bankrupt you.

Creaking indicates something is not right. And not always associated with the BB - even though that's where one thinks it would be. Read Sheldon's article on this matter:

http://www.sheldonbrown.com/creaks.html