First, the disclaimer: I'm a 1K on UA this year and a piddly nobody on EK. And I've been lucky enough to fly my last few international flights in UA C (thank you SWUs!), whereas I just came off an SFO-DXB flight in EK Y.
Still, though, the vast majority of my flights over the last 10 years have been in UA domestic and international Y, so I think I can make a fair comparison
EK WINS:
- Better service. More FAs than United Y, it seems, and -- unsurprisingly -- a bit less harried.
- In flight entertainment... by many, many miles. Wow, quite a selection of movies and TV shows and on a large, wide screen! Though please get a usability expert to give your ICE the once-over, okay? I had a bit trouble navigating through it, and my goodness, the two new'ish flyers to my left were simply baffled :-(.
- Amenities kit, even in Y. Nice touch!

- Food. I'd say it even came close to UA C, and definitely far surpasses UA Y. I mean, heck, we even got real cutlery, not plastic!
UA WINS:
- SPACE! Oh my dog, did I feel like a sardine in my EK SFO-DXB flight, and I'm just under 5'7" and 158 pounds, not a huge guy by any means. UA Y -- at least in E+ -- feels much, much roomier.
- Buy-ups: EK told me I'd have to pay the actual difference between my Y fare and their J fare. Or about $4K for the one-way trip. HA! HA HA HA HA! I would have felt bad about even charging my company $1K for the upgrade, but would have jumped at the opportunity nonetheless. But $10K+ total rt in J... I hate to start a war here, but how on earth do people justify this unless they're brokering million dollar deals right upon arrival...? In contrast, I've quite often been offered $500-$1000 international flight buy-ups w/ UA.
* * *
So will I fly UA or EK next time for my SFO-HYD/BLR trips? Likely UA. Yeah, I'll miss the IFE for sure, but I can bring my own entertainment (hello laptop with spare battery!) and even my own tasty food. But I can't bring my own space.
So, EK... if you offered Premium Economy with 30-50% more space, I'd consider paying 30-50% more for my ticket. Heck, I was ready to jump at your J product for a 100% premium (~$4K return vs. ~$2K), but alas, I didn't meet the minimum 7-day advance for that fare.
And if I could just get out of my window seat without waking up two other people, I'd be delighted. Is that so much to ask for?!