It most definately is not just a posh code reader; you can do live data, actuators, programming certain functions, etc. But it is not so that you can do all things you can with dealer tools... neither can other tools.
VAG for instance you can do coding of a number of things, Opel too (depending on model) and for multi other car brands too. Found that Peugeot and Renault are a bit hard at times and lacking functions. You especially need to have the right model selected to get right/most access with all functions for that particular car.