As you will mostly be out of FDM office and will be seconded on-site at client companies, this is something you need to know about before joining.
Work/Life balance will also depend on which client you join and which team as well, so it may be a little bit of the luck of the draw for you.
Also, you would still be competing with others in FDM for a position with the clients, so it's not as though you are guaranteed to get a role as soon as you finish training.