There are a couple of important factors in making a good decision depending on what you need to accomplish.
If you need
The problem is, everyone wants both. Here are a couple of options you can use to have your cake and eat it too.
If you manage a commercial sales force you probably want the standard follow-up system of activities linked to contacts/organizations. It has worked forever and good salespeople are comfortable with this system. The problem is that the notes are buried and hard to get to when viewing the contact/organization record. You can’t ask the salespeople to make notes in both activities and comments — they won’t do it. So you can add a workflow that creates a comment for every activity that has notes. This way you get the best of both worlds.
If you manage a retail sales force, the sales reps are less sophisticated and simplicity is important. We have helped our clients successfully implement filters that pull up leads/contacts for follow-up based on a ‘Next Follow Up’ date field. So the sales agent simply loads a filter, opens the first one, updates the comments, a status field and/or the 'Next Follow Up' date field, and goes to the next record. It’s simple and effective.