Should i read it?

My fav in terms of "modern knowledge" and "nation building".
Though I indeed skipped through some chapters too.

You can also disregard "harem" in tags.

You might want to just check manhwa(it has something like 60 chaps translated) to get the gist of it and whether you like it. 

It was slow and was too word-y. That, along with having a bad example of a harem. Anymore than 3-4 almost never works and even then, the members of the harem need to have significant character building and remain relevant until the end of the story. 

hmm I'd say I like the first half of it but the laters parts were kinda bland. Haven't read in a while 

I didn't like it
But I know some people who are fan of it, so there's that 

I liked the fact that Roland teaches his witches and slowly invent more things like guns and cannons after a lot of trial and error 

It's okay. Worth giving a shot, at least. If you don't like it, oh well. 

Slow and boring, i'm surprised i even lasted that long 

Personnaly I didnt like it, it was haremish and annoying.