Pros
Great training to close the gap if you have been out of work for a while. Access to LinkedIn learning even after you are placed. A good variety of clients available to provide a range of experiences. Good support especially if you are performing well. If you are on the bench (in FDM this is called "the beach"), you have the opportunity to join other training sessions that are running so it's a great chance to build skills in an area that interests you. Occasional socials available to you depending where you are based and which industry you are placed in. The FDM team in the office seem to have a lot of fun and socials but this is very different for the consultants placed at a client.
Cons
The benefits package is very limited - low pension contributions and salary. Once you are placed the support is limited, i.e. no extra training available even if it is critical for your specific role. If you are placed part way through training, the training will stop and you won't be able to complete it during your placement. If the placement is a poor fit, then you are stuck until the end of the client contract period (except in extreme circumstances such as bullying) Salary is not competitive for the role being done and your peers in the client firm will be on significantly more than you Career conversations take place every few months but seem a little pointless on long placements, when you consider that it is not in FDM's control and is entirely dependent on how you are viewed by your client. FDM cannot promise a particular role later on because client demand is unpredictable. Some people have been benched for months with no role.