It's been 6 years since I found out about the existence of Gluhen but it's only now that I actually watched it. But the timing was perfect.
Somehow Gluhen seems to be pretty much ignored in the fandom with about 95% of fics centred around Kapitel. And a mere week ago I was also very much biased against it. But now that I've watched it my attitude has changed greatly.
The main reason why I protested against Gluhen was the new character design, mainly Yoji's. But all in all apart from Yoji there is nothing to dislike about it, really.
Aya looks hot and omg that long hair!, Ken looks hot and really cool, Omi looks great too and thank god he's wearing pants now! In fact wouldn't it be lame if the only thing that changed about the characters in 4 years was the length of Aya's hair as it was in the drafts? In Gluhen the guys look more refined and mature. It's not just the animation that got better, it's like suddenly everyone gained a fashion sense. And even more importantly, their behaviour has changed too. Aya's gotten a lot more sociable, Ken's learned to control his temper, Yoji's gotten more fucked up and Omi's become...Mamoru. I never really cared about Omi but in Gluhen I couldn't help but admire him. There's so much more to the boy that you could ever predict. And Aya, I didn't think that I could love him more but I do now. Overall I think all of the characters got a lot more depth.
It just really felt so right somehow, watching it now. It's been 6 years for me and 4 years for them and it's kind of like we all matured in our own way. It's like our paths have crossed again after all these years.
The first 5 episodes are hard to digest. There's only Aya and two new guys and it's so sudden and foreign. I even began to doubt whether it was a good idea to continue. Then Yoji and Ken appear but at first everyone seems so distant. But then towards the middle it gets more and more interesting and when Omi comes into the mission room and gives his little speech it's like a family reunion and I got all Aww~ So towards the end I found myself really pumped up. The final battle was very fun since we get to see so many characters at once. I was cheering so hard. Like, "Oh, look! It's the Crashers! And wow Schuldig looks cool! And oh my god Nagi, he's become so Emo! XD" According to canon it was the last time they met as four.
When I was watching the last episode, I even cried a little. The ending was pretty sad. Yet it was also fitting somehow. Good thing I know everyone survived. Well, at least for another couple of years. Then again the whole Weiss universe is sad. There are no happy endings in it. But there's so much to it.
Basically, Gluhen is like an improved Weiss, a mature Weiss. Compared to it Kapitel seems so childish. I really wish there were more fics and about Gluhen. There are so many points to exploit. I was quite surprised at how concerned Aya was over Yoji. Surely in Gluhen he got that much more human but still. He basically saved his life and he even left his katana with Yoji and after the fall he stayed and was looking for him. Not to mention all the Aya/Ken.
Also I have to say I absolutely loved the soundtrack. While I had most songs before I realized I was missing quite a few and somehow I missed both endings. I really like Stone Roses and especially Tomorrow. I don't really like Koyasu Takehito but he's got one of the most amazing voices ever and I have to give him all the respect for creating this dark and exciting world of Weiss.