So, there’s this discussion going on at IWSTI (there are actually tons of threads like this…this is just the most recent one):

http://www.iwsti.com/forums/faq-newbie-forum/266142-2014-blown-motor-4000-miles-wtf.html

It revolves around the fact that someone’s engine blew up at the 4000 mile mark.  The guy left a ranting and short blurb that his motor blew up and he thought Subaru should give him a whole new car.  Several people asked him for the circumstances around his engine woes (was the oil at the proper level, was he bouncing off the rev limiter a lot or was launching the car, was the engine raced when cold…), but he never returned.  It is speculated that he was trolling, but the post is now spiraling into a free-fall argument of Subaru being negligent with applying the OEM tune or if these people with engine issues are at fault.  Let’s face it, people with tunes still have ringland issues, so sometimes, a tune isn’t the end-all-be-all answer…as well, the ringland may’ve already been damaged before the tune was applied.

Two posts in particular within that thread are full of knowledge:

http://www.iwsti.com/forums/3945737-post45.html

and

http://www.iwsti.com/forums/3945794-post50.html (and it includes a dyno chart with AFR measurements before and after a tune, but I’ll also post it)

Please read these links, especially if you’re worried about your Subaru’s engine.  Even if you decide to stay on the stock tune, you can still be a bit more knowledgeable about the subject-matter.