I actually purchased that one. Such a waste of money. Kinda why I will never buy another Kingdom Hearts game other than the story being done over and over.
Days existed mostly because Organization XIII was so popular. It was a fanservice game, really. I think its unfair to stop there just because of that game though. Just skip the DS games in general. From what I've heard, Dream Drop Distance is about on par with BBS.
Birth by Sleep had some great gameplay, I loved the fusing of the commands and Ven, Terra, and Aqua were all different enough (strategy wise anyway) to be interesting. I like Aqua's moves the most, but Ven's got Faith/Salvation and that bitching tornado magic move...soo uuuhhh. I can't decide.
The English voice actors for the trio were flat and dull, Aqua having none of her noble speaking voice which made the Japanese one great. And hey, what do you know? It's another story where Not Ansem is the not-so secret boss and Maleficent is starting some hoodoo. Haven't. Seen. That. Before.
I think it's release for the PSP was sorta a shame. Hardly anyone had one which made it's player vs. player level kinda worthless. (I only bought one to play BBS in fact. It was Miley Cyrus/Hanna Montana pink <3) It's clear Kingdom Hearts was not as important to Square as much as Final Fantasy 13. And they've neglected Kingdom Hearts 3 for so long, most of their older fanbase has outgrown it and it's tropey, hackish storyline. We're not gonna accept table scraps like it was sirloin steak.
I'm surprised. I found Aqua to be the most frustrating to play, although I think the reason for that is that I don't like using magic and I don't like her voice. I'll agree all three of the characters had poor voice acting. Even Ventus, who had the same VA as Roxas did, sounded worse, although I think that was because of them having different personalities and the VA trying to make them distinct.
As for Not Ansem, who are you talking about exactly? Do you mean Xehanort's heartless, or someone else? Either way, I didn't know he was in the game. Where is he? I wanna fight him.
As for Maleficent, in BBS she was just another Disney world boss save for her brief cutscene where she manipulates Pete. I don't think there's anything wrong with her causing trouble in her own world. At least they didn't make her important like in KHI or pseudo important like in KHII.
Also its a shame you bought a PSP for the game considering the current HD re-release, although in that version there is no multiplayer (although I believe that may have been replaced with NPC fights? Not sure, not familiar with the PSP version).
In any case, I dunno. Yeah Square definitely cares more about Final Fantasy but its hard to blame them for that considering it IS there highest selling series.
As for the quality of KH games, I think the numbered titles will always get the most focus. I was extremely quality, II was extremely quality. I figure they'd do the same with III, especially considering how long its been in development. The trailers for it look promising at least.
And its not as if BBS was bad, even if it did seem like table scraps. I hear Dream Drop Distance is about on par with it too.
Though I have been told that there are two teams that work on KH games. One team made I and II and the other made 358/2 Days and RE:Coded. I dunno who did BBS but I believe based on what I've heard that its the Days/Coded team.
I've also been told that III is being worked on by that team, which admittedly is worrying. But we'll see. Things could turn out better than expected.
My view on the Unversed is that the creators needed a cool boss for Aqua to fight (And we can't have her fight Lady Tremaine and the Ugly Stepsisters...even though that sounds kinda awesome. They could try to rip her dress off and maybe the fairy godmother could help out...) but forgot that they didn't work like the Heartless. 
