MSP is a bit tougher for me to feel "happy" about using one because it's so centrally located. If you have any transcons, ATL-west coast, anywhere to AK, HI, Caribbean, I'd definitely use it on those routes. Mexico and Canada depends on O&D if it's worth it. Sometimes you will find 764 or 359 routes domestically, and I always try to use them on those.

If you're doing all leisure travel just be flexible with dates and look for flights that will automatically clear. Half the benefit of them is being able to relax from the booking date to the travel date knowing that the upgrade list doesn't matter.