1500 miles sounds reasonable, though a little on the low side (for an 8+ hour transatlantic flight), for inoperable in-flight entertainment. I would generally expect more compensation for a broken seat, but it sounds like your seat may not have been all that broken.

Feel free to respond to CO, thanking them for the gesture on the IFE comp, but that you are severely disappointed that they didn't take seriously your problem with the seat, and that you are considering taking your business elsewhere, even if it means making connections. And that a stronger gesture might encourage you to give CO a try again.

But if the $2k you paid for each ticket was round-trip, I don't think they'll miss you all that much, I can't imagine CO generates that much in profits from these deep-deep-discount BF fare sales. Consider they could cram 7 rows of 6 of coach in the front zone of the 757 -- that's 42 seats, or 2.6x as many seats as BF. Given that Europe fares are in the ~$1000 range this time of year, the "breakeven" on the BF seat (excluding impact of higher level of service) would be $2600 r/t, so you got a great deal.

How were you impacted by your seatmate's non-operational in-flight entertainment?