This is one of the best isekai manga I've read. It's not just 'power leveling' and 'harem' nonsense; the relationship between Ed and Tia is amazingly sincere. The first world's arc was competent (if somewhat abbreviated - oddly enough, I think it deserves to be longer), and it really puts a highlight on something that is a bit unusual in this genre:
Ed is devoted to supporting the people he cares about. His goal isn't something as petty as 'being the strongest' or 'getting all the girls', but rather to ensure that the people he cares about are happy and safe. The fact that he gets best girl (only girl!) Tia, who is just absolutely fucking adorable without being a weak or spineless stereotype. It isn't gone into in great detail, but Tia is legitimately strong, and she doesn't follow Ed around so much as she largely stands by his side. The plot thus far is rather more compelling and competent than the norm, and the art is excellent.
Again - it's important to note that Ed is never the Hero! He's a dedicated supporter, whose goal is to ensure that, this time around, the people he came to care about don't suffer the way they did before. He's heroic, but in a way that lets the Hero shine. He's not egocentric, and his happiness comes from making others happy. That's significantly more uncommon in this genre than I think people will realize at first.
We're part-way through the second world, and it's not just a re-run of the first world's story: The concept is similar, but the differences are stark. Plus, Mr. Waffles as an anthropomorphic canine hero is both hilarious and sincere. There aren't a bunch of cheap gags all over, and I'm honestly annoyed that there isn't more. This is good. REALLY good!
I'm calling this a solid 9/10, possibly even 9.5 - I want more.