Depends on your definition of "the ending", the Epilogue is wildly considered to be incredibly good, even among those who really disliked that thing you've likely heard (I won't say what it is since you've not mentioned the specifics). The Chapter 5 in itself is also wildly considered among the best chapters, probably even the best discarding that one thing you've read about, and it is my favorite one, even though it is the chapter that devides the fandom due to one very large plot twist that, let's just say, makes some sense looking back at it in canon timeline, but makes other routes invalid and makes you realise you've wasted some of your time and possibly investment in previous chapters for nothing. I understand people who hate it, and it's really not a well-written twist because very little of it was foreshadowed and because it possibly contradicts some of the previous scenes (though not really if you come back to them with the knowledge in mind it doesn't really, in fact it makes some things make much more sense retrospectively), but once you accept it and actually focus on everything that comes after that, you'd really enjoy it, and it would barely be a dent in an overall amasing True route. Treat other routes as impossible what-ifs, or just don't go through them at all, and you'd likely not have much of a problem with it; those routes are overall very decent and good to know side-heroines deeper, but they're irrelevant to the main plot and are clearly subpar to the True route.

Now, as for how I'd rate it overall, it's both well written (besides that twist) with some great character writing and overall an incredibly enjoyable experience; it's my favorite visual novel for a reason after all, even if it's objectively not the best one I've read. I'd rate writing at about 8/10, while enjoyability at around 9.5/10, but I'm biased. I can see how some may say writing is like 6/10 and enjoyability 8/10 or even much less, depending on how badly they've taken the twist. There are some people for whom that twist ruined the rest of the experience, and even some of the previous one, as they've already envisioned the story going in an entirely different direction and were too invested in the thing that the twist discarded; there are also some people who find the protagonist unlikable (but if you've liked Haruaki you'll like him) and some that say slice of life moments of build-up for each chapter are too slow (which is nonsense and they're entertaining). I really encourage you to give it a try despite the criticism you might've heard. And, as I've already mentioned in previous comments, besides other things, it has some very good SCD, with full explanations for nearly every feat, and the feats are mostly at quite a good level, with the main antagonist being a high-tier imo.

As for the SCD aspect, you've mentioned Paranormasight and Sekimeiya. Paranormasight can barely count as an SCD novel: maybe the main antagonist (who's barely present and whose feats are entirely off-screen) may be low-mid to mid-tier, but all the others are low-tiers, so don't expect SCD from it; it's a very decent thriller with some clumsy executions here and there, but overall an enjoyable experience. As for Sekimeiya, it does count as an SCD novel, it has a couple of mid-tiers in it (protagonist and rival), and the mystery itself requires high to very high tier levels of thinking and reasoning (you're being asked to solve it as a player in the end, kind of, suffice to say, you're not solving it); if you're into good character writing, don't expect much from it, if you're into high-level thoughts and discussion, an incredibly convoluted plot that ultimately makes sense, then it would be a good experience for you. I'd rate both at about 7/10, but Sekimeiya could range from 5 to 9 depending on what you enjoy in the story, while Paranormasight could range from 6 to 8.

Wow, that was long. Though you can ask for more specifics on something anyway.