While hardly considering myself an otaku considerably immersed in the subject, I do have a particular interest in Ecchi (primarily because it's not as disturbing as most hentai). However, just like most erotic mediums, most ecchi suffers from being reliant more on fan-service than plot. I won't go so far as to say Queen's Blade is devoid of this, it isn't, however it manages something that resembles plot, albeit a rather basic one. The saving grace though is that the characters seem to actually have some development that makes the rather bland plot work. While it more-or-less plays all it's tropes straight, a lot of humor and sympathy is written into the characters that actually makes this series watchable and not fall victim to "skip to the good stuff".
The plot itself is about as interesting as any other anime or movie based off a fighting game (the only difference being this is a Pn P
fighting game). We end up rooting for many of the main characters as they fight in their "There can be only one" tournament whilst knowing right from the series get-go who the de-facto winner is. The series still manages to tie up nicely giving you the warm fuzzy feeling inside, and I'm not referring to that feeling in your pants like during the many clothes shredding combat scenes.
Altogether if you're looking for an intelligent well written anime, this isn't really the series for you. If you want a good fantasy ecchi with quality animation, lots of naughty bits, humor, and a story that manages to make the naughty bits seem less contrived, then Queen's Blade certainly qualifies.
Visuals: 5/5 - Excellent animation, awesome fight scenes, and all the fan service you could want!
Audio: 3.5/5 - While the sound effects are quite well done, some of the female voices border on the pure annoying (Nanael). The music is also very forgettable.
Story: 2.5/5 - It's not that the story is bad, it's just very standard fantasy/fighter fare, the end of the series is a foregone conclusion, though it's execution is done quite well, it still manages to feel bland and uninteresting at times.
Characters: 4/5 - Considering that series was pretty much based of character sheets and biography there is an ample amount of character development present.