Asking because the XB6 I have is getting a bit long in the tooth, and I am noticing a lot of slowdown with its WiFi signal, and I'm looking to maybe update my equipment (it's the only piece of equipment I have that hasn't been updated over the last 6 years).  

I have Fibre+ 750 internet.

I'm also asking because when I asked over the online chat, the person on the other end said that I couldn't because it required Fibre+ Gig, which seemed not correct (I also half recall having the choice to update the modem when I signed up for Fibre+ 750).  

If not then I will have to inquire about replacing the XB6 with a new one if I can't figure out my current one's potential issues.