3FG is better qualified to answer your question than me but I will say yes. (:-) Until now I have not had any success with OEM universal remotes controlling a "Comcast" cable box. The Sony RM-VLZ620 is very configurable. If it's not listed by a code the Sony can either learn by pointing at the unit until the unit turns off, or you can point the units remote at the Sony remote and teach it, or you can customize individual buttons. Not bad for $25.
Comcast Xfinity X1, XR2 remote, Martin Logan sound bar with OEM remote, Sony KDL 46hx800 tv, OEM remote