I admit to having gone there too... I had a 6h layover from LGW-MSP, MSP-SFO, so I took the light rail to MOA. I thought I would go down and go through the aquarium (I went through as a kid and have great memories), but I was surprised to see that they were charging $16.50 for admission. Ouch... obviously my childhood memories are missing some details . Anyhow, I went through, did some shopping (postcard + dinner), got back at MSP, had the TSA agent look at me funny for entering with a CONNECTION ticket (with a LGW-FASTTRACK sticker on the ticket jacket), but still made it back with plenty of time for a worldclub snack.

All in all, I think a quick run to MOA can be a nice diversion, although to be honest next time I have a long layover in MSP I'm thinking about actually taking the train into Minnie and doing some urban landscape photography rather than just burning time at MOA.