So far these 6 chapters spawn the story till 8 of October of the common route of the VN, I presume that more were released, but no one picked interest in scanlating them...
As someone that has played Rewrite, I found it interesting picking up the manga version (while I still hope for a anime someday, preferences goes to White Fox), IMO it was worth reading, especially if you enjoyed playing the VN like myself.
The character design could be more prettier, but still you can easily understood who is who, and some characters I actually like the design almost as much as the VN. And for a manga adaptation, they didnt skip any important stuff, so you get a good recap of the first 7-8 days of the common route.
If you have never played Rewrite, I would say, give this a try, if you enjoy it then I would reccomend playing the VN, as this 6 chapters are not even nearly 5 % of the story length you would find on the VN.
So if you really enjoyed the slice and life, mixed with a bit of mystery, you will love playing the VN, and be ready if you do, you will be playing Rewrite for a long time.
Conclusion, overall it is a fair adaptation of the original's, it was worth my time, seeing stuff I had to imagine, drawn as a manga, seeing some cute Lucia's and other characters behaviors.
I cant elaborate much more because this is at the very beggining of the overall story, and there arent anymore chapter scanlated.
For me it gets a 8.
