I believe the issue has less to do with the manufacturer and more to the issues that Craig brings up regarding the difference between DC current draw and AC current draw. Too many people think that if the circuit draws 100mA then that's what the transformer needs to be spec'ed at, when it's much more complicated than that. Then they claim using "massively oversized" transformers as a feature when likely they just stumbled upon the right number. Also, failure to specify a particular temp rise and then holding the vendor to that number is another problem.