I've had nothing but great experiences on Asiana. I find their service to be excellent. I love their Korean menu choices (the Bibimbap and Ssambap are great) and they always keep me generously supplied with Piper Heidsieck. The Smartium seats are nice but a mattress pad would make them more comfortable.
It's been a year since I last flew on them, so I'll be interested to see next month when I fly SIN-ICN-JFK if things have gone downhill.