NIW is significant for China and India people.
South Korea may have as many as 5/6 PERM applicants to China's PERM applicants, but I assure you, SK's NIW applicants is just a small fractions of China's NIW numbers.
Well, in my opinion, NIW lost its short time advantage over LC since the start of PERM in March 2005. If you do have a stable, professional job, EB2 PERM is probably faster nowaday.