There is huge variability in EK seats, even on the same aircraft type. The new J seats on the A380, the 777-200LR, A345 and some of the 777-300ERs is great. Others are pretty bad.

There is no way to use CO miles to upgrade on EK.

And there is one route where you can earn CO EQMs and bonus miles, on one of the LGW-DXB flights. That's it - no other flights in the EK system.