The chemistry between the leads is alright (not as good as in What's Wrong With Secretary Kim). The plot is very much standard fare, with every cliché you've seen a dozen times.
The idol fandom topic is done tastefully, but doesn't have the same effort put into it as say Reply 1997.
The supporting characters are alright: sometimes funny, sometimes not, but never obnoxious.
There is an average amount of filler scenes and plots.
A perhaps average amount of product placement, but in a more stupidly obvious way than you'd expect.
The OST is okay as well (but nothing I'll remember for months).
I didn't sit in agony for hours waiting for any painful plot arcs to end, either. In a way, I'm most thankful for the scarcity of pointlessly negative story elements, with the writers instead going for themes like happiness and healing.
All in all: no serious complaints. Serves its purpose as a fluffy, no-stress show.

On Netflix and such you have content missing compared to the TV version: https://mydramalist.com/32293-her-private-life#comment-12329955

The special you can watch either before the show or after a few episodes; it has some minor spoilers regarding characters and plots introduced a bit after the start.