I have a 2009 WRX Premium. I wanted an STi, but even almost being 25-years-old the insurance is outrageous.
I love my car, the interior is awesome, all bells and whistles are worth in my opinion (fog lights, heated everything, etc...no Navi). I got a great price on it and not sure if I would have benefited from getting an STi.
As for maintenance, I've only had one problem and it was covered under warranty. Something got "hot" and exploded in my rear diff. Other than that, it's a great, fun car to drive every day.