Yes, those settings should be fine. The grouping by completed date variation is useful if you want to look at data where there's a greater range of dates, especially if you want to only look at part of it. You can close the groups that don't interest you, and save it as a perspective with the restore expansion box checked to have it always be shown that way. This is how you make a view that only shows things completed today, for example.
Also, if you're interested (and not afraid of using the command line), it is possible to get the completion date column to show both the time and a more friendly date. For example, the two tasks I just checked off in my database show "Today 8:31 AM" as the completion date. Read about the details here:
http://forums.omnigroup.com/showthread.php?t=19114