IMO, the good news is that it's better than Isekai Tensei. The bad news is that Isekai Tensei starting with the third volume quickly devolves into just a step above stream of conscious journaling with a dash of dialog for seasoning.

I don't think I ever had a problem with The Water Magician's science. Most likely because it became quite clear that the MC is full of it; baselessly self-important with delusions of gradure. Not really a character that's taken at face value.

I think for people who want words on a page the LN is for them. For people after a story, then the manga and anime provide it while still capturing the feeling of the LN. For people who want some light reading, I highly recommend looking elsewhere.