You cant give an accurate appraisal on each as they are just random letters and not brandable or pronounceable??
Unless you research each one individually in Google and find out how many acronyms each has, how many companies use the same letters, how old the names are, what other extensions are taken etc etc
They are not good letter combinations (in english at least) so there wont be a lot of acronyms, but you never know what acronyms they have in Chinese?