Pros
Language Link is certainly one of the better established organisations in VN. They are reasonably professional, punctual and take care of all legal documents and proceedings. You will be supported with plenty materials and advice from staff. Overall there does seem to be some option for career development within the company to some degree.
Cons
School placements differ, and many in the 'Schools Link' system, even the 'Premium' ones, will bring you challenges. Sometimes these issues related to your teaching are internal to the school, and there may be little LL can actually do. Micro-management is also a possibility, and there are contractual details based on lesson observations, evaluations and subsequent bonuses that I found a little frustrating. Students are also sometimes asked to give teacher's review scores, which are also used as part of this 'evaluation'.