Anyone know the difference between a regular and "accessible" seat? Seems on my flight 4K is accessible while 4A is not.

I usually go for the window seats since I fly mostly solo. I've flown on the upper deck of the A380 on a few other products (e.g. OZ and EY F) and the curvature has never bothered me (that said, I do hate those windows since you can't really see anything). A bit disappointing that EK shoves 4 suites across on the upper deck when EY has 2 and SQ puts theirs on the substantially wider lower deck.