Who are the go to tuners these days if I wanted to chip my XC90?
Had a look though search, but most threads on this topic date back a while and at least one suggested tuner no longer seems to have an operative website.
If you have the D5 163/185 in place - I would recommend MTE remap. I had mine done by Don Norchi (Google him). Fairly painless process, although you do need a windows XP machine to run the somewhat old software.
I had my 163 remapped and its really changed the in gear acceleration.