When I try to negotiate my player's contracts, I tend to not use any agent for the sole reason of I want to deal with everything myself. As much as it's great to have agents to figure out what's going on. sometimes the agents have interests that aren't mine in mind. I obviously would like a contract to the best of my interests and I don't need an agent inserting his own opinions and interests into the mix. In addition, I feel like I'm smart enough to figure out the minutiae involved with contracts and so I won't get too lost when trying to figure out a contract. In addition, I (strangely enough, I know) love figuring out a contract with teams including the specific dollars per year, stipulations, options, and whether I'm tamperable or not. Having an agent would definitely help me figure things out but it would remove a lot of the fun in dealing with the contract myself. Thus, I would negotiate my own contracts and let other people deal with agents instead.