I wasn't super into it. Tom Hanks was fine, but I wish there was more of him. I honestly wasn't invested in the writer guy's plot that much - adult dude estranged from his father; haven't heard that before...
That much I will agree with - it felt more like the Mister Rogers aspect of the movie was something of a subplot to the arc of the writer who was interviewing him . . . but then again, I think that was actually supposed to be the point of the movie.
I will say that in the movie itself, Tom Hanks was actually a little better as Mister Rogers than he seemed in the trailers, which came off more as a Forrest Gump-esque kind of performance, with the slight southern drawl and all.
I expected it to be a full autobiography on Mr. Rogers', as opposed to being based more on an article that came out in 1998.
I really like the scenes that simulate parts of the show (the beginning, the sequence leading to a film about making magazines, the ending). I wish they'd done a little more of those (or had the visit from Mr. McFeely come a little later).