Personally I like Sasaki to Miyano better as I just like the characters better and it feels like the pace is faster in Sasaki to Miyano.
The pace in Hirano to Kagiura feels a lot slower than Sasaki to Miyano. I think it’s partly because the Sasaki is more proactive and affectionate with his love than Kagiura and it feels like neither of them are actively trying to make progress as much.
In Sasaki to Miyano, the comedy consistently makes me chuckle and the subversion and playing around with tropes makes the story entertaining. In Hirano to Kagiura, the tropes are ever present, but not subverted or played around in any way. Now this isn’t necessarily a bad thing, and a manga can still be good with it, it’s just that it feels like it’s been done before many times.
Characters in Sasaki to Miyano feel less like tropes, while you can fit Hirano and Kagiura directly into the cliche boxes. That being said, Hirano and Kagiura are still cute, but I don’t think they have the level of chemistry as Sasaki and Miyano.
All in all, Hirano to Kagiura isn’t a bad manga, it just had bad luck to be placed in the same universe as Sasaki to Miyano and be compared to it. In my opinion Sasaki to Miyano is a better manga in pretty much all aspects, but Hirano to Kagiura is a new manga with only 4 chapters so far with room to improve.