So, I had done a review with my first impressions but now that I've heard the songs a lot more, I've changed some of my opinions, for better.
In general, I love the stage. It might be missing some power we are used to see in Team K, but there are no BAD songs (like Hatsukoi Dorobo and 16nin Shimai no Uta in K4, those were a must skip for me). I would not skip any on the K5 songs.
Opening drama: That was great but freak. Seriously. I mean, I loved it but I still think Akimoto was high when he planned it. I loved Sayaka's storm-like entrance. Haha. Now I wonder if they are gonna do the same every time or if they're gonna change it once in a while.
School uniforms: One of the ugliest I've seen. The top is OK, but the skirt is terrible T_T Plus, the ones who have the jackets buttoned looked fat.
Tenohira: Many people have complained about a slow song at first, but that apart, this is one of the most beautiful slow songs I've heard from AKB (together with Sakura 2008 and 10nen Zakura's B-sides). I loved the song from the very first time.
Saka Aagari: I found it kind of average at first, but now it grew on me easily. Like most of the songs, the chorus is the catch point.
Amazon-like costumes: Jesus Christ

They ALL (well, almost) look hot. Sayaka has such an amazing body

And my Sae came back, with her short hair, hot outfits and cadential movements.

Great clothes.
Hitei no Requiem: THIS IS TEAM K. Hot, rhythmical. This song is excellent! I loved the voice arrangement. They did this in many songs and worked perfectly! (like they did in Mori he Yukou in H2). One of the best songs in K5. One of my favorites, too.
Sono Ase wa Uso wo Tsukanai: The Amazon costumes don't fit this song. But oh well, I don't mind seeing that outfit once and again. The song is ok, it had to grew on me after several listening, though. Good, but average.
End roll: EXCELLENT! I loved it, my second favorite unit song. It reminds me DA PUMP so much

Despite other comments, I think the costumes are perfect. They all look great. Natsumi really surprised me, also Nonti. They are great dancers. I loved both here. Well, in summary, I could listen to End Roll the whole time, and it wouldn't bother me.
Wagamamana Nagareboshi: HORRIBLE costumes. When Kana and Erena appeared on stage, I thought: "I'm gonna hate this song". And guess what... I luv it

It's so from the 80's. It made me go singing "
look up, look up, look up, the sky is falling...". Don't know why!!!!
Ai no Iro: Oh Sae, oh Sae. You're so hot yet so adorable. I agree, this song has too many people. Ohori should have gone to Kasai's unit and and Naruru or Oku to Erepyon's. Despite this, the song is good. VERY GOOD. I felt it was too short, though. The dresses are insanely cute, but I don't know why Sae keeps looking hot and moving as she were going to seduce me...
Dakishimeraretara: This is the unit song I liked less, I think it's coz it's too long, like "does this ever end?". Shorter would be better, IMO. It's too relaxing, so you begin to fall asleep, like with sirens melodies or something. The clothes are hot. I loved how Asuka and Nacchi showed their shoulders little by little. For a moment I thought the blouses would fall down. LOL. But well, me liking it less doesn't mean I didn't like it. Asuka's voice matches the rhythm perfectly.
Mushi no Ballad: I'm so, so so so so in love.

It's might not be the best rock ballad in the world, but Sayaka does such a great job, she's so into the performance, she suffers so...

She turned a good song into a marvelous song. *goes fangirling* The outfit? Show the belly pls! And wear a Fedora! I loved the tutu.

And plaid works for me, so I don't complain.
Frilly costumes: These ones are so horrible, so horrible, so horrible... So horrible that demonstrate the girls look amazing no matter what they wear. They still looked great, even with that freaking golden belt.
Furishite Maneshite: That stupid guitar solo at the beginning is amazing! That made me love the song, and the chorus, of course.
Pretend you love me, do as if you hugged me... >___< More songs like this, please!
Umi wo Watare!: Took me a while to like, but the chorus ended up blowing my mind. Again, that voice arrangement. Flawless.
Machikado no Party: Team K turns everything into a party. It took me a while to like this song but well, you know the story. I like it now, a lot. T__T
SUPER GREAT NECKTIE CLOTHES: zOMG HOT. Sayaka, as usual, look really good but... Sae just made me go 1000 times gayer. LOL. Wearing all that white stuff, HOT! She looks so handsome.
Fan letter: Thanx to this song I'll write fan letters until the day I die. Another amazing ballad. Best ballads are in K5!
PLAID WEIRD CLOTHES: I loved these. If I could I'd wear one of these. Seriously.
Fugiri: It does the same on me as Furishite Maneshite and Hitei no Requiem, so I love it. And I loved the dance, the girls rocking their heads was a blast. Another TEAM K-style song, IMO.
Hanpana Ikemen: People might hate it. But Ange loves it! This is also a total Team K song. Why? The first lines are all with that low voice the other teams just can't match.
To be continued: I don't understand why they are wearing those
night robes on... The classic ending song. Thanx for the Saeyaka moments. Huh huh!
That's it. I love the stage, there is nothing to do about it.