We are looking for a firm in Taipei to work with long-term. We’ve tried a local one with pretty disastrous results.
The input writing style uses a lot of subordinates, which seems to cause all sort of grammar issues with the translation. It ends up looking like something no Chinese native speaker would ever write themselves (we have native speakers at the office who could not understand the translation without having to refer back to the English version). Despite several attempted revisions, the output is not something we’d ever want to publish.
The writing also includes a lot of financial and technology jargon that has not been as much of a problem, but probably should be mentioned to delineate what I mean by a “GOOD” firm.
We’ve tried e-lance and guru with similar (and surprisingly expensive) results. Looking at maybe a semi-crowd-sourcing approach as with http://www.tolingo.com as well given their claimed multi-person proofing.