The red-eye promises a full workday on both ends, but it only pays off if you can rest on the plane. Chosen well, it saves a hotel night and a day of travel. Chosen badly, it costs you the sharpness you needed for the meeting it was meant to protect.
Reach for the red-eye when you can protect the morning after for recovery, and avoid it before anything that demands peak focus at 9 a.m. Be honest about whether you actually sleep on planes. For some people the math never works, and that is worth admitting.
If you take one, set up for rest: a window seat to lean on, layers for the cabin chill, and a hard stop on screens once you board. Treat it as a night of sleep, not a bonus work session.