I'm also new to this whole "mileage run" thing - I've done two thus far and revolved both around something I love to do, visiting baseball parks (dugout box seats at Wrigley over Labor Day weekend and playoff tickets at Oakland this past weekend). Now that I'm all qualified again for next year, I'm looking at next year's Sox schedule to plan where/when I'll go next year (i.e. I need to see a game at Petco, so I'll definitely be doing BOS-SAN the weekend of 6/15!).
I don't think that I could spend all that time on a plane and not stay at least one night or do something in the city I'm visiting; but if I end up doing more of these, that may change (I've only had status since April, and don't know how I ever flew without it; nor can I envision ever NOT having it again).
Since I'm only Gold, and don't foresee myself flying enough to get near Platinum qualification levels (I qualify on EQM's, since a lot of the fares I purchase or fly for work are 50% EQP's), I don't usually feel the need to add additional segments (I like to get where I'm going without spending an inordinate amount of time at airports/on planes, however that is something that may change if I decide to get an Admiral's Club membership to make the 7-10 trips I take per year more pleasant).