The thing is, the 3.0 TFSI supercharged V6 is highly tunable so a standard Q5 3.0 TFSI is capable of 12.8@105 with just an ECU tune. That makes it quicker and faster than the SQ5 for less money.
Now there is more to the SQ5 than just acceleration such as the more aggressive body work, wheels, and better brakes. These items can all be added in the aftemarket though on a base Q5 3.0 TFSI.
A Q5 with the 3.0 TFSI starts at $44,400. The SQ5 starts at $51,900 and of course also can and will be tuned. The price is not a major difference but the base car is clearly more of a performance value.
With the launch of the Macan S though if one is interested in performance the Macan is clearly the better choice considering it is lighter, has a dual clutch transmission, a twin turbo V6 motor, and is actually cheaper than the SQ5.
The biggest threat to the SQ5 seems to actually be from its own sibling over at Porsche. Test numbers below.