[Age of Reason]

I'll be darned--those propellers seem steerable.

Clever.

But is the added maneuverablity worth the added complexity?

[hoagy62]

Yes, two of those pods ARE steerable. QM2 has 4 of them, two fixed, two that can swivel 360 degrees.

Those pods are called "azipods" because they can "azimuth" (naval term for swivel). Rather than being connected directly to the engines by a drive shaft, all the propulsion motors are in the pods. The drivers are electric, getting their power from the main turbines.
Because 2 of the pods can swivel, and because she has 3 manuvering thrusters at her bow, she can technically put herself into dock WITHOUT a tug. (Tugs will be used, however, for safety's sake.)

Most major cruise liners are now being built exclusively with azipods, since it alows for faster docking and greater manuverability.

As for the complexity...it's really not all that much more so. Ships engineers and pilots love the new capabilities.