Just picked up an '11 S60 T6 AWD. She needs rotors. I'd like to get something a bit better than stock, with a tad more bite when you hit the brake.

Is there a consensus on a good setup?

 

The rotors don't provide the bite. The pads do. Swapping to stainless lines helps in responsiveness and and pedal feel. Typically the larger the rotor the more surface area you get which helps in heat dissipation and stopping power but stepping up in rotor size can be cost prohibitive. slotting or drilling a rotor helps get the gas and spent pad material out helping keep your brakes cooler and more consistent under heavy loads. Switching to a high temp brake fluid will help keep you away from brake fade when your pounding the pads. Are you planning to autocross, race, or just want a bit more around the town stoppage? The intended usage will very much determine what changes make the most sense for you and your car.

That being said, if looks are a primary driver stop tech makes slotted and drilled rotors that will swap in for your stock rotors, just realize that some folks have had problems with them arriving in the box being more the five thousandths out of spec. Personally I haven't experienced this problem. Being more than 2 or 3 thousands out will cause your pedal to pulse when braking and if the rotors our out of round unequally, pull to one side.

 

I seem to recall using them on my Saab 9-3 a while back and they did the job well with not so much black dust.

I was just wanting a bit more around-the-town and highway stopping power. No racing or A/C here.

Oh, and a while back I got a set of cross drilled Brembos for my other Saab. They were out of spec too. Took me a while to realize that was the problem as the rotors I had replaced were also warped, vibrating at highways speed without braking and very much more when braking. It never occurred to me that new rotors might be warped. I had them turned and everything was fine. Go figure.

 

Well if you have the depth in the wallet there is a polestar kit for your S60. Viva Sells it but it's steep.

Polestar S60/V60 Front Brake Conversion Kit - ViVA Performance

That kit would also require a rim swap keep things from hitting.
Viva also sells a Stoptech kit for a bit more than half the price:

ViVA Performance Big Brake Kit, Volvo S60/V60, XC60 - ViVA Performance

Both are overkill for the road. Personally I would use a set of new stock Volvo rotors and Akebono pads. A call to ipd to see if their stainless lines will work on a P3 might be in order as well. If you live in the mountains then the combo would switch to a set of StopTech slotted rotors with the caveat that you check the run out on the rotors before you drop the car off the stands.

FYI When I say long term I mean 60K plus.