RachelRuth
A good system novel for me would that it would go into detail, like the way the system is structured, novels like "The legendary mechanic". That novel is detailed as fuck, you can tell how much effort the author put in. However, I generally don't enjoy original system novels as I believe it's the easy route in writing a novel, (you just gather the amount required, and you gain the ability/power with no explanation given, it just happens, it's pathetic), except for traditionally published novels, the authors do it for a living so they're generally well written and structured, and they also give some background information about the ability gained. It's somewhat like the system isn't even necessary for these protagonists, those are the readable ones for me.
As for the quality of the novels, even when the "write your own novel" function came out, the quality was still lackluster compared to the traditionally published novels, and even now the quality is pathetic, some novels ranked high on the leaderboard use colons, not quotations, FUCKEN COLONS.
For sentence structure and paragraphs, the ones I read tend to have max 7-8 sentence paragraphs, but those only occur 3-4 times in a chapter and the rest are relatively short with 3-4 sentences. But, the novels I read, the grammar, in general, is good, the authors know what they're doing, so it's readable, unlike some shitty authors on this site.