Here's a picture I shot 4 years ago that shows the Premium Economy seats in their upright and reclined positions. The recline is different from a traditional economy seat. The seat bottom actually angles a bit in the reclined position and slides forward. This gives you more recline with less seatback intruding on your neighbor behind you.



While the economy section seating on these A340-500s's is the best in the business (36" pitch,) the seats are the same width as other airlines' economy. To be clear, Premium Economy is not an "Economy +" product with a little extra seat pitch. It is a different seat entirely, and in a 2-3-2 (7-across) configuration, rather than 2-4-2 (8-across) in economy. The specs for the Premium Economy seat don't do it justice. I believe they indicate it is 19" wide, only 1" wider than economy. But as you can see below, there is a much wider arm rest, and a gap between the two seatbacks. For me, the benefit is that these seats allow my arms to hang freely, rather than having my arms and shoulders scrunched up (as a traditional economy seat does.) And that makes a big difference on a flight that is blocked at 18 hours! Typically, THAI has been charging a few hundred dollars more for PE. I haven't flown it recently, but for quite a while they had an upgrade for about $200 each way. That works out to about $10-$15/flight hour. Well worth it to me.



These Premium Economy seats are better than typical domestic first class, and have more seat pitch than domestic first class too. (42")