Summary: Because of side protection & 70lb weight capacity which my husbands liked about, we purchased all three car seats from Britax for our kids - one Boulevard for our girl(5yrs)and two Marathon for our boys (3yrs &16month). Even though these were too bulky & cost a lot, I thought it's ok since these offer safety for my kids (according to description of product). And these seems fine until my kids grow around 40lb & 3yrs old.
Summary: Ive had this car seat for a couple years- the main reason I purchased was the safety features. My 3 year old has figured out how to unlatch the clip that goes over his chest. Before you invest $$$ like we did make sure you get a seat that requires you to press a button then the top of the clips like most grocery store shopping carts. the plus side to this seat is the fabric is very easy to remove to wash.