Having more agents means you can service more requests concurrently. So if you had a large transaction volume but they all came from a single user in series, multiple agents wouldn't make any difference. But if you have many users and their requests often overlap in time, it will make a huge (positive) difference. But of course they will use more memory, this isn't much of a factor for us, but I guess it depends how big your data sets typically are. IIRC, the AppServer broker dynamically manages the # of agents, you can set minimums and maximums and trim and such, but it should react to increased load fairly well on its own.