We had the same dilemma, but went for the travel system with the seat that could be slotted onto the chassis in the end. We don't use it often, but it has been useful. We don't have our son in the carseat for more than 2 hours, but he wants feeding every two hours anyway, so this isn't really a problem. It is convenient to have the choice, so I would recommend it. Agree with the advice goven above re: size and wieght, make sure it will fit in the boot of the car and obviously, consider how many steps you need to get it down if you live in a flat.