ATC probably sees it, since equipment is in part of FPL (items 7 through 18) which ATC sees, but I guess they don't use it.
OK, will try to file 8.33 on couple of next flights - as you said, it really can't do any harm
BTW, I've searched through Eurocontrol's page for implemention of 8.33 channel spacing below FL195 that will require for all aircraft that operate inside Europe to have 8.33 capability by 2018. Will we really have to throw away all that steam avionics from 70's and 80's that still works flawlessly (more or less), which cannot be modified for 8.33?