This is a tricky one because it really depends on YOU whether this book will work for you. 
- It is funny with dark humor and astute observations about situations, things that people say, casual sympathies, etc
- BUT this gets repetitive. It is nearly the same theme throughout, so maybe after a point you might not laugh as loud as you laughed the first one.
- It is wickedly funny about divorce, the way we hurt others, the way our significant other hurts us
- BUT at some point you are going to feel the other emotions associated with these incidents (pain? anger? sadness? grief?) and you might think what the hell is the protagonist doing? Is she completely fleshed out? Is this denial mode or something else? Address the elephant in the room.
- Also sometimes you wonder is this humor? or are you hurting? or is this humor from pain? It is a confusing spot to be in as a reader.
- protagonist on self destructive mode. (I don't mind such characters, so it was alright for me). If such characters bother you, then this book won't work for you.
- Also I feel this book will speak differently to you depending on where you are in life (millenilal? boomer? gen z? married? divorced? committed? single? after a recent break up? Or basically how much of other people and their lives you've had experience with). There were parts I felt a younger me would have laughed at, but the present me just gave an exasperated sigh. There were parts I thought 'ugh, we learn the hard way' but I know at some other point in life I would have simply read past it.

About comparisons to other books. I like Ghosts by Alderton more for the humor on dating life. While Really Good, Actually covers themes similar to Sorrow and Bliss by Meg Mason, the latter is more deeply fleshed and emotional and made me cry bucketfuls. I would say, do not looks for comp titles, but simply read Really Good, Actually if the blurb excites you.

Overall funny, breezy, wicked but repetitive.