ImbracableCrunk,
I thought that too because there have been issues with momentary screen blanking and internally generated V-speeds with U11. However, some operators have chosen to go ahead with U11 and take advantage of all the good things it has to offer.
The plan is to keep both U10.8 and U11.0 in the sim and see how U11.0 performs for a while. If there are no instability issues using U11 in the sim, then it goes to the line.