If 2-4-3 causes imbalance, then you would think the first half of the plane could be 2-4-3, and the second half 3-4-2. Simple solution. Even better, just have the first part of the cabin 2-5-2, second 3-3-3, 3rd 2-4-3! That way everyone is satisfied!
No airline would have coach being 2-2-2 because that is the same number of seats abreast as a narrowbody 737/A320. I don't see how sitting in one of the middle seats of 2-4-2 is worse then being in the middle of 2-3-2 but you're entitled to that.
3-3-3-3?? Yeah a plane big enough for 3 aisles, that's pretty good. Is that a blended wing type thing?
4-4-4 is pretty good also, except for the poor soul sitting at the window! Even that would require another couple feet more width then the A380. In a charter layout, the A380 could support 3-5-3 which is only one more seat than 4-4-4. And imagine when serving food, the tray needs to be passed all the way down the row, or the FA could climb over everyone. Plus the pasenger would need to scream what they want so the FA could hear him/her since the he/she would be so far away.
3-6-3 has as many as 4-4-4 and may actually be possible because it is just as bad as the middle seat on 2-5-2, just another person with that dilemma in each row.
I myself prefer 2-5-2. I hate having a window and being 2 seats from the aisle. Atleast on 2-5-2 that only happens to one person, except he/she has no window. So I'll take my chances. Obviously 2-4-3 would be the best.
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Sometimes I go about in pity for myself and all the while a great wind carries me across the sky.