This thread is basically to say getting the RD is worth the extra $$$.
Brought my V60 RD in for it's first oil change today and the dealership gave me a V60 T6 (Sport Chassis w/ 19' Wheels) as a loaner. Here's a few differences I found I like about the RD that you won't get in the normal T6.
1. Engine:
I know 25hp and 26lbft of torque isn't much, but the RD's power delivery is awesome compared to the T6. The car just feels more alive. I say Polestar software is a must. I felt that the gearbox programming on the RD is a bit harsher, they never mention anything in the brochure or any technical docs, but it feels very different. My RD shifts a lot quicker in sport mode than the T6, but then it could be the fact that my RD has learnt my driving style.
2. Chassis
I know on paper, Volvo claims that the Sport Chassis is the same as the RD suspension, I can honestly say that it is not. The T6 feels a lot softer, same route I drive to work everyday, with the loaner I was not able to pull the same speed through the same corner as the RD. The T6 felt swayed around the corners and the RD feels like it's on rails. The ride on the T6 doesn't feel as sporty and soaks up the bumps a lot better, mind you I have 18's on my RD and not 19's like the loaner. One other thing I have to mention is that the RD has a different setup in steering speed as the normal T6. I don't need as much steering input in the RD to make a fast corner as the T6.
3. Brakes
One of my BIGGEST noticeable difference is the brakes!!! The T6 brake pedal feel is squishy and there's quite a bit of fade before I feel the brake kicking in. The RD brakes has less pedal fade and feels more immediate than the T6.
4. Seats
The driver seat in the RD sits lower than the T6, I like that. In the loaner I set the seat to the lowest setting and I still felt that I was seated a bit high, felt like I was seated like driving an SUV. Speaking of seats, the RD seats are more bolstered than the T6 leather sport seats. There are better hip support in the RD than the T6. With the sport seat in the T6, I didn't feel as "tucked in" as in my RD. Since I have nubtex and not the full leather, I can't comment on the "butt holdingness" of the seats because it's not apples to apples. I have driven an RD with full perforated leather seats before and it wasn't as slippery as the normal T6 leather seats.
In Canada anyways, the $2000 extra doesn't seem like it's worth it for the RD, but I have to honestly say, after my experience, it's well worth it. When I bought my 2012 S60 T6, the price difference was $5000 between the RD and the T5, that's why I opt out of it. If you really think about it, in the RD, you get bigger brakes, a RD tuned sport suspension, Polestar tune out of the factory, RD aero kit, RD seats (perforated leather), faster steering, many standard that is are options on the normal T6, compared with the fact that the Polestar tune itself here is $1700+labour to add on. That $2000 difference to get so much more is a bargain.
I'd say, if you are going to option your T6 with all the bells and whistle AND the considering getting the Polestar tune afterwards AND you're not picky on colours, just go with an RD. I had a Caspian Blue S60 before, and I wanted that same colour or the power blue for my V60, but neither were available for the RD
which kindda sucked. I wanted the Rebel blue, but I like metallic colours and the rebel bue isn't.. so I chose white instead, that was my bad 
Enjoy
Brought my V60 RD in for it's first oil change today and the dealership gave me a V60 T6 (Sport Chassis w/ 19' Wheels) as a loaner. Here's a few differences I found I like about the RD that you won't get in the normal T6.
1. Engine:
I know 25hp and 26lbft of torque isn't much, but the RD's power delivery is awesome compared to the T6. The car just feels more alive. I say Polestar software is a must. I felt that the gearbox programming on the RD is a bit harsher, they never mention anything in the brochure or any technical docs, but it feels very different. My RD shifts a lot quicker in sport mode than the T6, but then it could be the fact that my RD has learnt my driving style.
2. Chassis
I know on paper, Volvo claims that the Sport Chassis is the same as the RD suspension, I can honestly say that it is not. The T6 feels a lot softer, same route I drive to work everyday, with the loaner I was not able to pull the same speed through the same corner as the RD. The T6 felt swayed around the corners and the RD feels like it's on rails. The ride on the T6 doesn't feel as sporty and soaks up the bumps a lot better, mind you I have 18's on my RD and not 19's like the loaner. One other thing I have to mention is that the RD has a different setup in steering speed as the normal T6. I don't need as much steering input in the RD to make a fast corner as the T6.
3. Brakes
One of my BIGGEST noticeable difference is the brakes!!! The T6 brake pedal feel is squishy and there's quite a bit of fade before I feel the brake kicking in. The RD brakes has less pedal fade and feels more immediate than the T6.
4. Seats
The driver seat in the RD sits lower than the T6, I like that. In the loaner I set the seat to the lowest setting and I still felt that I was seated a bit high, felt like I was seated like driving an SUV. Speaking of seats, the RD seats are more bolstered than the T6 leather sport seats. There are better hip support in the RD than the T6. With the sport seat in the T6, I didn't feel as "tucked in" as in my RD. Since I have nubtex and not the full leather, I can't comment on the "butt holdingness" of the seats because it's not apples to apples. I have driven an RD with full perforated leather seats before and it wasn't as slippery as the normal T6 leather seats.
In Canada anyways, the $2000 extra doesn't seem like it's worth it for the RD, but I have to honestly say, after my experience, it's well worth it. When I bought my 2012 S60 T6, the price difference was $5000 between the RD and the T5, that's why I opt out of it. If you really think about it, in the RD, you get bigger brakes, a RD tuned sport suspension, Polestar tune out of the factory, RD aero kit, RD seats (perforated leather), faster steering, many standard that is are options on the normal T6, compared with the fact that the Polestar tune itself here is $1700+labour to add on. That $2000 difference to get so much more is a bargain.
I'd say, if you are going to option your T6 with all the bells and whistle AND the considering getting the Polestar tune afterwards AND you're not picky on colours, just go with an RD. I had a Caspian Blue S60 before, and I wanted that same colour or the power blue for my V60, but neither were available for the RD
Enjoy