How can we really tell if a 'keris' is a good one or not?

Answer 1

With all objects possesing powerful spirits - - - you simply know - - - it seeks out your eye you touch it an electric tingle signals this is the one. It is all 'Mana,' 'power, the life force of the hardened metal the life force of the smith who fashioned it - - - IT will tell you if it is a good or one you should shun.

http://en.wikipedia.org/wiki/Kris
"""The kris or keris is a distinctive, asymmetrical dagger indigenous to Indonesia, Malaysia, Brunei, Southern Thailand and the southern Philippines. Both a weapon, and spiritual object, krisses are often considered to have an essence or presence, with some blades possessing good luck and others possessing bad.

The kris spread from the island of Java to many parts of the archipelago of Indonesia, such as Sumatra, Bali, Lombok, Sumbawa, South Sulawesi, Kalimantan, and to the Southeast Asian areas now known as Malaysia, Brunei, southern Philippines, southern Thailand, and Singapore.""

Peace

(PS And the last time I caressed a wickedly twisted Malaysian blade it was a good one)

Answer 2

I am not sure what you mean by good, but to the Javanese people it is a sacred weapon. A man is not man unless he carries a keris. A good keris could take a year to make by an Empu. When an Empu made such a dagger, he had to make it high quality in both spiritual and physical sense. So, if this is what you are asking, then this is the answer.