I reviewed the Jamis Commuter 4.0 for Road Bike Review. Note that this is the 2008 model. There are a couple of substantial additions in the 2009 model: a rear rack and dynamo hub with LED headlight are now standard on the Commuter 4.0 bicycle.
I'll have a follow up review in a week or two, so if you have questions or additional observations, please leave a comment over at Road Bike Review and I'll be happy to incorporate them. Thank you!