Make sure you drive the 2017 Forester. Even the 2016 will have the classic Subaru noisy cabin so it won't compare well to the Q5. For a lightly used Q5 my Audi dealership had demos, which they have to sell as certified used so 6-year 160,000km warranty.
The Subaru sits lower on the road, but still has great visibility. Its power is much punchier than the 3.0L Q5 but both get you up to speed in the same amount of time/distance.
For the $15k difference (new) you'd really have to love the Q5 and want the slightly higher ride height. From a practical standpoint the 2017 Forester is tough to pass up.