I can only speak about transactional practice areas. I’ve spoken to practitioners. I can tell you that the answer is a resounding no. Much of transactional practice isn’t about law anyway, so additional legal knowledge in the form of the LLM isn’t going to help you. Transactional practice areas require logic and commercial acumen - your LLB and formal education should have equipped you with the former, and you can pick up the latter with experience in practice.

So, from a transactional practice viewpoint, all the usefulness LLM is an expensive sabbatical. Nothing much more.