I assume that every outfit uses the FCOM/FCTM/QRH/OMA/OMB combo. There are plenty of differences, which are specifically described in something like OM-B. Line experience shows that certain practices from AB are written to be legal, but don't take the realities of line flying and experience into account. This is where Airlines start to deviate somewhat to try and mitigate risks in certain areas that have proven noteworthy on the line. They are not major deviations, but definitely changes that make life more workable on the line.
If anyone would ask me to use the AB procedures only though, I would simply be forced to revert back to the FCOM as instructed during TQ training. The FCOM's seem to be written in a generic enough manner to be applicable. The differences shouldn't be that big from previous versions, the plane has been around for more than 20 years.