It depends on what you import, of course. A fairly simple document usually looks about the same. More complicated documents usually need a bit of tweaking. The latest version of Pages has improved it's import compatibility considerably.
Still, I would not recommend Pages for people who are constantly moving the same document back and forth between it and Office. As long as your import and export needs are occasional, Pages is a very nice word processor. You wont' find anything better for creating a well laid out document on the iPad.
I don't consider Google Drive a very good substitute for Word, or at least not on the iPad alone. The editing tools are very basic, and the final document does not always print out as it appears in the editor. It is good for simple documents, but not as a good layout tool. The tools on the main Google site are much better. I you plan on doing your final formatting there and only adding text and pictures on the iPad, that would work fairly well. Still not as powerful as Word, but most of the tools are there, and they work.
Other popular Office compatible apps with varying degrees of power and compatibility are:
Documents to Go
Office HD
QuickOffice
Polaris Office.
And if you can live with the limitations of desktop-made-touch UI and needing fast internet access to work on your documents:
CloudOn
OnLive.
