You asked all the wrong questions and none of the right ones. Determine your
needs and then purchase the software that better fits your needs. If your primary need is to create and share
Office documents, then purchase
Office. If your primary need is to create documents for your own use and that can be shared as hard copies or as PDF copies, then go with
iWork.
To answer your wrong questions:
- Software quality. Office 2011 is a Microsoft suite. It is a big bloated mess. Quality does not enter the conversation in discussions of Microsoft products. However, if your needs allow you to purchase software based on quality alone, then you do not need Office.
- Unnecessary/Unused Features. This is the very definition of Office. Microsoft never saw a feature that it didn't like. OTOH, Apple provides the features required to produce beautiful documents. Your talent and skill as a user can more than make up for iWork's smaller feature set.
- User Friendliness. Microsoft? Apple? Come on!
- Footprint Size. Office is a big bloated mess. Do the math.
- Exclusive Features. Office has everything including several kitchen sinks. There are no plumbing fixtures in iWork.
You appear to be fixated on features. If you need an application that includes a command to create vertically-oriented tables on even-numbered Tuesdays, then
Office is probably your better bet. If you want to produce beautiful documents, then
iWork will serve you well. That said,
Keynote presentations make
PowerPoint presentations look like the scribblings of a child.
I will end where I began. Assess
your needs. Purchase the software that better fits
your needs.