I think Ellen and Ruth make good points- the team is only as good as it's weakest link and there is potential for miscommunication. I think it is more important to go with an agent who is on board with their sellers, helps guide them to pick a realistic price for the listing, and has a solid marketing plan that they follow through with. The team approach doesn't serve the seller unless they have faith in all members, and their roles are very clearly defined.
That being said, I AM part of a team, but we have very separate roles in the transaction. I have a web marketing background and do all of the promotion for the listing, and the CA/NV broker salesman I am partnered with has 30 years working with investment properties and luxury homes, and focuses on the contracts and negotiations. This really works well from our standpoint, and we feel our specialized roles best serves our clients.