This topic is interesting.I feel malaysian puteh are more sought after by puteh keepers.I have heard puteh from vietnam,japan,taiwan and africa n their vocal is not as nice as comparing birds from either indonesia or malaysia.
IMO malaysian putehs do have better sound quality birds but not every bird from there.As birds do fly or migrate so there is no certainty that particular part of area will always produce the best putehs.
The famous Kota Tinggi putehs are well known to have good melodious singing sound quality maybe bcos of the clean water found from the river there but for what i heard there is no longer any putehs there (Not sure if it's the demand so poaching of putehs there have reduce the bird population tremendously or isit the water quality there doesn't interest the birds anymore?Hmmm)