Questions on long-haul economy: China Eastern vs Air China
I'm considering China Eastern and Air China for a possible trip between Asia and Europe or Oceania. I've never flown any of the Chinese carriers long haul (I have flown them domestically and intra-Asia and didn't mind it), but their fares are just so much lower...
I've read the past ten pages of threads on this forum plus searched here and on youtube but still have the most basic of questions (my apologies!)
My general sense is that economy is fine on the newer planes, inasmuch that one can survive economy for 12-16 hours, although most of the comments are from folks who normally fly U.S. carriers.
For those who have flown both (or even one of these two airlines), how would you rate them? In particular, I'm interested in
General seat comfort (width, pitch)
Ability to secure advanced seat assignments
OLCI functionality
Hub connections
IFE (particularly interested in the options for kids)
How frequent are aircraft swaps
Are there any particular planes to avoid?
My preference is to fly Air China, assuming the fare is eligible for some credit on either Singapore or United, but then I saw that they have a 3-3-3 configuration on their Dreamliner... Then I read a report where someone mentioned that there wasn't any individual IFE on the China Eastern A330 (although I'm pretty sure there is individual IFE on at least some of their A330s).
Thanks!