So thankful for the anime reminding me this manga existed, can't believe I binged it all in a week after dropping it a couple years back.
@electro_neanderthal the MC is a bit insufferable but does become redeemable despite his... "quirks" like Meliodas. I'd say the turning point for me was chapter 43 when some of his past is revealed. I'd say that's where I got invested in the characters and the story, and it picks up from there. I wouldn't say he necessarily matured over the manga since he continues his antics, but he does become less of a selfish prick as he accepts his role as the hero.
I completely understand if you (and others that are hesistant) don't want to continue the manga due to his character, or how ecchi the manga is. I personally loved how goofy the whole adventure is, even during the serious parts. I'd compare it to Konosuba, an alternate universe where Kasuma has a thigh fetish and becomes an actual hero, with many twists and unexpected turns. Overall I'd rate it around 8/10, but 9/10 simply on enjoyment.