In C:
IAH-ORD/IAD-VIE (avoid the sEWeR, fly OS longhaul, get in VIE earlier)
VIE-FRA-IAH (avoid the TSA, get better CBP, avoid the 787/767)

In Y:
IAH-FRA/MUC-VIE (E+ longhaul, avoid the 787)
VIE-MUC/FRA-IAH (E+ longhaul, avoid the TSA, get better CBP, avoid the 787)