Just spent 11.5 hours in what should have been one of the most comfortable seats in Y (12J, MCE, aisle) and honestly it was one of least-pleasant long-haul experiences I've ever had:

- Extremely narrow seats. Yes, more narrow than a WN 737-300. This means that even in an aisle, the guy in the middle is constantly pushing you, poking you, all night long. It's not his fault, it's just that the seats are too damn narrow.

- Narrow aisles. This is amplified by the fact that everyone in an aisle is leaning waaay into the aisle to avoid getting poked, pushed, rubbed constantly.

- Good leg room in MCE. But, see above.

- Freaky blue/green hazy glow through the windows all morning. The electrochromatic windows don't block anywhere near all of the light but what they let in is a very hazy, weird glow (blue on one side, green on the other). When you're in this weird haze for many hours it really becomes very unpleasant. I was so happy when they turned off the "shades" when we finally landed and actually got natural sunlight.

- Yes, cell phone signals are pretty much non-existent. Blocked by either the electronics or the electrochromatic windows, or who knows.

- It is quieter, but given all the negatives above, who cares?

- I didn't particularly notice the higher humidity levels but I did notice the lower cabin altitude. It kept me awake much longer.

Avoid.