I did this trip to London and back recently. It was full both ways. It was pretty uncomfortable in zoo class, stuck in a middle seat, but still better than going through Dubai and their wretched security (having a metal hip this makes a big difference).
Preferable to Emirates particularly in the quality of the food and not having to sit trapped, often for about an hour, behind a mountain of plastic wrappers getting horribly dehydrated because EK only serve water and juice in tiny containers and nobody can get out of their seats. Is this deliberate? (Thanks you QF for the water bottle provided) . The entertainment choices were great and I had no jet lag at all.
The only complaint was arriving at LHR at 5am and having at least three plane loads of travellers being dealt with by just ONE immigration officer for non EU passports, (no E gate for non EU people) I was in that queue for about 1.5 hours and I was near the front. So not a great time of day to arrive, Heathrow need to get their act together there.