I think this work will be received differently by different people. It represents something in manga that I think alot of people are opposes to, but which some people enjoy greatly. Overall, I'd be worried if something like this ever became a major mainstream hit, but I think it serves its role well as a niche title.

Story: 95% of the time its a harem romantic comedy, but it occasionally veers into battle shonen. The story in most chapters is really more of an excuse for fan service, so you might argue its pointless to even consider, but its a decently original take on the harem genre, being a harem of ghosts, witches, and ninjas.

Art: This guy really should just draw porn. I don't mean that disparagingly, but he does draw some really cute monster girls, and is even pretty good at drawing battles when they pop up. Its hard for me to really judge his overall talent when 90% of what he draws is tits, but he's at least very good at drawing that particular thing.

Character: They're likable, but tend to fall into the cliches of the genre (ie the male protagonist is given very little personality at all, and the female harems personalities are defined mainly by how they pursue the protagonist).

Enjoyment: I think the main barrier to enjoyment is that there's too much fanservice. Don't get me wrong, fanservice can make good anime, but I think this manga could learn that sometimes less is more. Literally every single chapter is 40% either naked or cosplaying female characters. Its hard to get excited for this in such a long running series, since by this point, YOU'VE ALREADY SEEN THEM NAKED 10+ TIMES. Its god ecchi, but I think it gets tired after a while.

TLDR: This is To Love Ru on steroids. If you like ecchi, this is perfect for you. If you're not so into ecchi, is still decently entertaining for a while, though you might get bored fast.