The Target Retirement funds are good in themselves, but once you start to have multiple retirement accounts, it will be more difficult to keep track of your asset allocation (unless you have Target Retirement funds in all of your accounts).
It sounds like your next step should be deciding what you want your asset allocation to look like (and your first decision is what percentage of your portfolio you want in bonds). If you decide to go the Target Retirement route, first decide what percent you want to hold in bonds, and use that to choose your fund. In other words, don't choose the Target Retirement fund based on the date that you think you will retire.