I just wanted to throw my thoughts about HSiFS somewhere in this topic.
I think this game is better than LoLK in some aspects. The music seems more atmospheric (especially Okina's themes along with 6th stage theme and extra stage theme - I think they're amazing), I've gotten more into the game's plot and characters. I like the new sub season mechanic too, although it can be abused (summer, for example). The game has become slightly easier, which (for me) is a better thing. LoLK was too difficult.
The idea of placing the true final boss in the extra stage isn't bad, but despite that I'd prefer that extra told a new, related to the main plot story like in the previous games. In terms of drawings, I especially like Reimu's portraits. ZUN's skills certainly improved.
I'd say that ZUN didn't fail at making the game fun. HSiFS doesn't have any truly troubling game mechanics, thanks to which it became much simpler. I still wouldn't recommend it for beginners, though. We've got better candidates.
And something slightly off topic...
I doubt Okina will make an appearance in Antinomy of Common Flowers, as, after all, it's 15.5 and not 16.5, but if she will appear in a fighter someday I bet her story will be intriguing. She reminds me slightly of Yuuka and Yukari, which should make some interesting dialogues.