Disclosure - I am a financial broker and my firm offers both execution-only and advice services.
The rules of execution-only dictate that the client must choose what product is most suitable for them, what product provider they want and what fund(s) they want their money to be invested in. So an execution-only service is mainly aimed at people who know a lot about what they're doing.
If a broker is to provide any advice, they must first obtain a fact-find of the client's financial circumstances. This will determine what product is most suitable for the client. In this instance, the broker might be advising the client on the relative merits of an ARF, annuity or Vested PRSA. Then a broker will recommend a product provider - some pension companies offer better deals than others for larger amounts or different age groups etc. Once a product has been selected, the client's attitude to risk will need to be measured and choice of funds will need to be discussed to suit the requirement. A broker must document the recommended product and fund, showing why it is the most suitable for the client's requirement and why other products were not recommended.
As you can see, there's a lot more work involved in an advice transaction than an execution-only transaction so you can expect to pay more for advice. But if you're happy to choose your own product provider, product and fund(s) then execution-only deals can be very competitive.