i agree with you, i've already seen the entire series and i was completely disappointed with it. the first ep was probably the highlight of the series. The animation keeps its great quality and nice action sequences throughout the series, but this was about the series only good point. The characters don't really develop at all during the series, finishing it out in much the same mind frame as they start it. The main plot line of the series is also ignored for the majority of the series. Now, I'm not against episodic anime, but I do like a bit more of story progression during a series.
btw, sorry to go off topic but have you seen the new Hellsing OVA yet meryl ?