Pace 5268AC RG upgrade

I was recently sent a Pace 5268 AC RG when AT&T offered a free upgrade of my internet service from the 2Wire RG.  I have been using a 2Wire 3801HGV RG for the past several years and it seems to work fine not a fast as it should be but it works. The problem is that I have coaxial cable running from my NID to the 2Wire RG and it appears this will not work with the Pace 5268 RG. Can anyone confirm this? If I don't want to change my wiring setup, am I limited to using the 2Wire RG? And if that is true how do I return the new Pace RG? Thanks for any clarity than anyone can provide.