The problem I've run into with Office 2 (on my iPhone), is that it cannot open .xlsx files. At least not yet. This is an increasing problem for me as time goes on.
Other than that it worked pretty well once you figure out the UI. Dropbox integration was very nice.
Except for the issue I mentioned above about QuickOffice, where it can't stay in text entry mode even within the same cell, I like the QuickOffice UI better than Office 2. But either gets the job done.
Either of these packages, BTW, has somewhat limited support in the Word tool for formatting changes. You can change fonts, sizes, bold, italics, and so on, but don't expect to be able to change a paragraph style or anything like that. Depending on what you are trying to accomplish that may or may not be a problem. All I typically do with word documents in this environment is review and spot edit, for that they work fine.