I only have one experience with each (though I cleared an SWU 3 months out on 5pm FRA-IAD for next month), but I snagged an op-up MUC-ORD on a Thursday last June, as a 1P. I'd concur your upgrade odds are good at MUC. Food and drink at the lounge was good, but the layout made it seem more crowded than it was and wasn't that conducive to working.