When I first had it in mind to possibly buy a new Civic I was dead set on the 2.0 L NA motor. I thought it would be the best choice for long term reliability. But after test driving the new 1.5 L turbo I was thoroughly impressed, I've never driven a Civic with as much mid-range grunt, even last year's 2.4L Si motor didn't pull as well. Any way you cut it the 1.5l motor just seems to be a better choice, and as you noted a quick tuning mod can get you a decent amount of power gains.
If I'm not mistaken both motors are Direct Injected, I've been a bit concerned about DI motors for the last while but it seems like you can't get away from them and everyone is moving towards them.
Honda has engineered some really good technology into the 1.5 l turbo motor to give it some reliability benefits, I think it will be a reliable motor in the long term as long as one takes proper care of it with regular maintenance. I have also been really impressed with the CVT tranny coupled to the 1.5L turbo, they seem to work really well together and there doesn't seem to be any performance loss from it.
2016 Coupe Touring - Blue
2002 Honda S2000 - Silver with Blue and Black custom interior. Garage Queen.
2015 Jeep daily driver workhorse.