Personally I agree the songs are just not the same, the reason people may superficially think that is the arrangers are the same. The area this has hit most for me is C-ute's songs (I know it seems like they're trying to move them to a more serious group and away from purely an Idol feel) but there's something almost undiscerningly missing for me, and maybe that's the influence of Tsunku. The most rational way I can put it across is I think in sometimes I think members are singing the wrong lines, that those line don't suit the members or their voices as well as Tsunku normally would select...he knows them like no other song-writer ever will. That's the thing that will probably never be the same for H!P.
Other songs like for example Angerme's last single tracks that people claimed as Tsunku-esque turned out to be only in some ballpark 'style'. Style makes up a whole lot of the substance in pop music but you can't just add a brass section and say 'there you go "Tsunku"'. Compare TMS or Sukatto My Heart to Gashin Shoutan and Nana Korobi as that's the style people are thinking of but these aren't close to the same quality. I'm not even saying those songs are 'bad' either just different and not as good... except for the ending of nana korobi.
Taiki Bansei is also held out as an example and it still seems a lot of people's hope is that Takui will be the new Tsunku. It is really good and even better than a lot of Tsunku's recent songs but the odd thing is that more than ever before the studio version has none of the power of the live version. This is because they tried to 'Tsunku-ise' the song one of Takui's strengths is getting that live raw power. Which at least they did it a lot better with Girls Be Ambitious for Ju=Ju. I think they should stop giving us a watered down version of Takui songs and give it both barrels, for concerts and in the studio.
Where some of the best non-Tsunku H!P songs have actually come from is doing exactly that - not trying to be 'Tsunku' but to simply allow the writers/arrangers to go where they naturally come from. Otome no Gyakushuu (apart from the forced dance break
) and Sheishun man man naka are good examples of this. I hope the company get more confidence after a while to hire people because they will put their sound and style into things. Tsunku has constantly evolved his sound, he himself largely moved on from those big-band/funk inspired songs. Are the people who are writing for H!P now so inspired by the same music? I'm not sure, I'm worried that they may be afraid of the risk of people turning away because it's not Tsunku too much. Even that Tsunku going has allowed them to go backwards when he himself saw the folly in redoing the same old stuff. (Head Office already asked Tsunku if he wanted to resign before he was even diagnosed with cancer).
There's no way I would've got into J-pop and H!P without Tsunku's music, no way at all. But I'm not a Tsunku or nothing person, Tsunku opened the door of J-Pop for me (I was already listening to other Japanese music) but I walked through it and came to admire and love lots of other composers, lots of other songs and groups. Also whilst good music continues to be really important for me I went way beyond Idol groups being just the music to it becoming about the Idols as well. That means even though I think the road hasn't been totally smooth I don't actually see myself turning away from H!P because Tsunku is reduced in role, if anything those other sides of Idol fandom have grown far stronger because I do connect so much with so many of the members now. Whilst I think the music doesn't always have that feeling, some of the non-Tsunku songs are still great some even better. I hope they don't become too conservative and instead use the number of groups they have and the fact they don't rely on that one composer to become more innovative for at least some of those groups.