It's a straight forward job, once you've done it, it will take you half the time the next go around.

I personally would either paint the hats on the rotors (instructions on Volvospeed) or get some that are zinc plated. The rust that accrues on rotors is pretty unsighlty, especially if you want to show off your holes. While your in there, maybe paint the calipers too?! You don't have to be flashy and go red, I went black for a clean subtle look.

I did this job on our 95 855. I did not have any real problems.
Others have reported problems with tight bolts or getting the
old rotor off (hit it with a bigger hamV=er being the common
response). I live in the Bay Area in California and we have dry
winters so I suspect the lack of rust and minor corrosion made
disassembly easier.

I did have some problems figuring out where to put the brake grease
(I used Bay 13 instructions). I basically greased everything except
the pad surfaces (of course). When re-assembled I could see some
grease on the back of the pads since a portion of the pad's back does
not touch anything. No harm done, but next time I'll be neater about
it. Good news is no squeels (I did front and back).

Once the new parts were in place I noticed that brake performance was
way down. It took about 50 miles for the pads to seat. Once seated,
brake performance was as good as ever. So, if it feels like it takes
more effort to stop right after the service then just give it some time
to break in. A lot of the brake grease burned off at this time, too.
Kind of odd to see smoke comming from the calipers. That stopped
rather quickly, though (I suppose I used a lot of grease but that seems
to be the recommendation).

Oh, I used OEM parts from Volvoparts.com. New OEM rotors also include
new bolts for the caliper pre-dipped in loctite. I guess Volvo wants
the bolts replaced when the rotors are replaced.

My personal opinion is that I see no need or benefit of the crossed drilled rotors, other than they warp faster. The mintex pads do eat rotors faster. The OEM rotors and pads work just fine, even though the OEM pads do leave a lot of dust. My OEM pads and rotors were $109 shipped.

You'll need either a lot of force/effort or extension to the 15 mm wrench that is used to unbolt the caliper bracket because the 15 mm bolts were covered w/ thread lock compound. OE rotors came w/ 2 new bolts that has this thread lock on them. If you are re-using the old ones, they need to be cleaned and covered by that compound.
*** the old rotor will NOT come off if you do not remove the 10 mm stud.