A few people that post here have used the ceramic pads and thought they worked very well. Haven't tried them myself but I had the same problem with factory pads creating an incredible amount of dust on my '93. I switched to Axxis (PBR/metal master) pads and dust generation has been cut dramatically. Brake performance has been better than factory pads. Going with a higher performance pad like Hawk or EBC will get you even greater brake performance for only a few dollars more, but I don't know about the dust generation on the 850.

On other cars I've owned almost every pad I've tried has been superior to the factory pads, both in terms of stopping power and dust generation. Was the tech you talked to at a dealership? If so then it's no surprise they're telling you not to use anything but Volvo pads. Overpriced and overrated if you ask me.