Is this game good despite the mid-low tier graphics?
There are better looking single CGIs out there, but that's only because of the limitations of a mediocre engine.
GIL3D is able to spin gold from straw, i haven't seen HoneySelect used in a better way yet. I don't know on which qualities you base your judgement of graphics in a game, but i believe comparing a single screenshot to another falls flat in a VN.
As soon as you incorporate factors like storyboarding, posing, framing, camera direction, facial expressions, background details and character designs, which are all absolutely essential in a
Visual Novel, there are in fact very, very few games which can hold a candle to Pale Carnations. Perhaps your personal taste made you believe that any HoneySelect based CGI can never be above mid-low tier, graphics wise, but i bet you will be surprised what is possible to pull off with this engine, if used by capable hands. So your (premature, since you obviously haven't played it yet) question can come across a bit insulting.
And to finally answer your question, despite the far better than average (compared to the competition) graphics, this is a very good game, certainly one of the best.