Having the IFE built into the plane alway creates issues.
At HP our IFEs are always MELed. INOP monitors, INOP headset jacks, or a completely INOP system. If it does work, you have no choice over content. First, a 6 minute infomercial about the wonders of Reno/Tahoe, then Big Mama's House II, followed by an episode of Cheers? Please...let's evolve...
I vote for offering entertainment units for rent at the departure gate like AS and YX do. Load it with a half a dozen movies, sitcoms, things for people of all ages and interests, and a ton of music...then rent it for $10 (comp for FC or DM Preferred) - use it inflight, turn it in at arrival gate.
The old KISS theory, you know?