I have had my Evolution for 10 years, and <70k mi on it. It is modded out, and it is a blast. But after having all that time with it, I am just feeling "meh" about it anymore. Not really bored, but not really excited about it. I was looking at a newer car just for some fresh blood, an updated interior, and better MPGs, and the 15 WRX seems to be the closest match to my Evo 8 as far as look and feel, not to mention I kind of just want to try out a different car maker as odd as that sounds.
I test drove the Evo X on 2 separate occasions now and just didn't like it. I didn't like the steering wheel, seats, interior, and "size/weight"-feel of the car. Granted I was able to tell at the bleeding edge it could probably outhandle my modded Evo, but everywhere until that point just felt more tame I guess. It certainly felt much-much heavier than my Evo and that was a big let down, plus the transmission felt really poor in comparison as well. The interior felt really meh and dated, and there are plenty of nightmares about problems with the car outside of it's powertrain (which is excellent in reliability). I don't want to deal with flimsy Mitsu build and finish quality, and while Subaru's paint isn't great, it's better than Mitsu's, that's for sure.
Overall in scope of things I don't think Mitsu's asking price reflects the performance anymore. In fact, the new STI really doesn't hit that as well. At one time EVOs/STIs were a bar above so many cars in performance. Now a days, they don't command that edge anymore and there are many cars near their price range that can match, or surpass their performance for the money. They're still great cars, especially if you live in a shitty state like I do where we have horrible winters, they just don't have that "wow" factor per dollar like they did in the past.
So I'm hoping I like the new WRX because it would still be a fun everyday car to me, and they are seemingly getting great MPGs to boot. I'm going to be doing quite a bit more driving daily soon here between work, school, and clinicals that I have to do in this program so the updated interior and better MPGs will be helpful. Plus, I'm at the point now where I would get this car, pay it off in 2 years, and then start going after a car and experience I lusted for years, an Ariel Atom.
As far as if you're looking for something new I assume, at this point I would probably go with 15 STI over a 15 Evo, and that's because the 15 STI seems to be more of a successor to the Evo 7/8/9 than the Evo X does in feel and performance (aka driving feel/experience). Plus even though Subaru's interior isn't "luxury" by any stretch, it's vastly superior to the Mitsu's in fit, feel, and finish.
Sorry for the long response, probably more than you wanted to read lol. If you have any questions about the 8/9/10 let me know. I know the cars inside and out pretty well, what you can expect out of them, and what mods to go for first and such.
Bro. Get a Pantera. Bro.