I found that OpenOffice Impress was slightly more difficult to use, and not as appealing to work with, but, the end result is very impressive.
It does support exporting in the Microsoft Power Point format, as well as importing.
The few templates that come with it, last time I checked, are very simple but nice looking and very professional.
Also, Impress works well with all the other programs. Ability to import Calc and Writer documents may be important.
