The 55-01 is a fantastic instrument, regardless if Korean or Indonesian. I've owned both and both were top notch quality. The weak link in this bass is the preamp. If you swap the preamp for any other quality pre, US Bartolini, Audere, Aguiar, Glockenklang, Darkglass, etc, the bass will come alive. The stock pickups are great, the magnets are in a reverse "P" configuration, but teamed with a less than wonderful pre. Swap the pre before you upgrade anything else.
That being said the stock pre is usable, but is very heavy on the hi end freqs, so you may have to cut the treble.
Other than that, I can't find anything else wrong with them. Skylines are fantastic, comparable or better than MIA Fenders IMO.