Subaru Outbacks had many engine problems before 2010. 2010-2014 fixed almost all the problems, and 2015-2018 hasn't really seen any engine issues. Between 2010 and 2014, the CVT had some failures. CVTs are good for MPGs, not for reliability or driving enjoyment. This is a big reason I would choose the Alltrack (or CX-5) over the Outback.
The Sportwagen is just a lowered Alltrack with a lower starting price and less off-road capability. It is available with AWD on the lower trim I believe, but not the higher ones. If I had to choose between the Alltrack and Sportwagen, I would choose the Sportwagen because I live in SoCal and don't even see rain more than 5 times a year. The Sportwagen will handle a little better than the Alltrack with the tighter, lowered suspension. This means the ride comfort will likely degrade slightly.
Out of all the cars we have mentioned, the 2017/2018 Mazda CX-5 is the one I would actually be willing to buy. A lot of people on this site including me often recommend this CUV for good reason. It is reliable, stylish, smooth, quiet, durable, fun to drive, and a great value. It has the best interior of any small economy SUV and is stylish inside and out. Automotive reviewers and myself could easily mistake the interior of the CX-5 for a $45k luxury CUV. The exterior styling negatively affects rear visibility a little and the interior and trunk are considerably smaller than other small SUVs like the CR-V, RAV4, and Chevy Equinox. The CX-5 is more reliable than the Outback and We recently bought a 2015 Mazda3 and love it.
The 6 cylinder 3.6i Outback is not really fast, but it is a huge step up from the 2.5i 4 cylinder. The 3.6i cuts the 0-60 time from 10.5 sec to 7.4. That doesn't seem like a big difference, but when driving it you will instantly notice. 10.5 seconds is slower than my 2016 Prius, and that is saying something. Adding to that, my Prius is quiet at full throttle and the engine never feels stressed. With the 4 cylinder gas engine in the Outback, the engine will sound loud and stressed out at full volume. The 3.6i comes in an expensive trim and you'll lose 3 MPG on top of that. For that price, I'd get the EyeSight package with the 2.5i Touring or Limited. The engine issues in the previous Outbacks were mainly with the 2.5i.