How Do Act! and MS Outlook Differ?

In My Humble Opinion
1

… and what are their comparative strengths/weaknesses? Are they essentially the same?

Thanks.

2

Outlook is an email client whereas ACT is more of a database for contacts. It really depends on what your needs are. If you need a lot of information about your client/friends, then ACT is your choice, but it does not have an email client IIRC. So you will still have to use Outlook or your favorite email client.