Content Services 6.2 is useful if you already have custom transformers based on the legacy approach, because it will allow you to gradually migrate them. Initially you will probably want to create new T-Engines but run them as Local Transformers attached directly to an repository. All of the transforms provided with the base Content Services are available as Local Transformers, so may be combined with your own Local Transformers in Local Pipelines. Once happy you have every thing working it then probably makes sense to add your new T-Engines to the Transform Service. The Migrating a Legacy Transformer page helps by showing which areas of legacy code are no longer needed and which sections can be simply copied and pasted into the new code. Some of the concepts have changed sightly to simplify what the custom transform developer needs to do and understand.