I usually find it decently easy, just speaking of returning the car or getting the rental and driving out of MSP. The Hubert H. Humphrey Terminal is even easier and you're out of the garage in no time.
The problem I've had for several years in a row now is that I haven't received the car that has been booked. And of course the lagguage, if the whole family is traveling, won't fit in the trunk. So I always try to make sure I get the car I know will have sufficient space - and get it confirmed, but it turns out it still isn't the car we agreed on.
Other than that, no problems at MSP!