Magic Users Club has a charm that makes it more than the sum of its parts. Even if you aren't taken by it, you'll find that its individual parts are at least above average.
Animation
The visuals have a slightly retro look, even considering its ripe old age of 11 years. The colors are simple, and the textures a little flat. While Magic Users Club's backgrounds look very boring, its character animations suffice without any bits of serious awkwardness. That alone makes it at least average. Its comic creativity, which extends past the typical SD characters and facial animations is what sets it just above par in visuals. The ability to have characters express internal emotions externally and in wacky ways is a big part of what makes animation such a great medium for comedy. While its not really punchline comedy, the chills we literally see go down a characters spine, or the crazy facial interpretations of romantic awkwardness are all gently amusing.
Sound
There's absolutely nothing remarkable about the voice acting, in a positive or negative way. The BGMs for the most part are pretty generic, orchestrated pieces that are used often and fit nicely into the background. There are a few rather outstanding tracks that remind me of the main theme from the original Willie Wonka and the Chocolate Factory. It's melodious in a light and whimsical way. These are the really dramatic BGMs, and probably the only noticeable ones. They sound great, and the string heavy melodies lend a seriously retro feel that seems to be inspired by 70's Hollywood music from the likes of Willie Wonka or Star Wars.
Story/Characters
The X-factor of this OVA lies within its story and characters. Looking at the deepest, foundation level of its premise, it is in Miyazaki fashion about a young girl discovering herself, finding her confidence, and/or growing into adulthood in a world at least a little more fantastical than our own. Indeed the female lead, Sae, is a full time high school student and part time magician (not to be confused with an illusionist) who wrestles with discouraging failures at her beloved hobby on a regular basis. Her optimism and determination usually get the better in the end though. Personality wise, she is something of a typical shoujo lead. She's a heavy underdog; someone who could be fairly deemed a loser. Inhumanly clumsy, awkwardly inarticulate, and hilariously narrow minded, one might even call her dumb. On the up side, like all shoujo leads, she has admirable perseverance and kindness.
A big part of the story of the OVA is high school life. As per usual with high school dramas, there's some love geometry, crush confessions, and general romantic cheese sprinkled liberally around. Like so many other Gainax works, sexual humor is stuck right where it doesn't belong. Innocent as the rest of the story may be, the main male character is a typical harem lead. He's good natured but can't help his perverted fantasies. From his fantasies stem accents of harem-esque ecchi humor.
The real charm of Magic Users Club is that all these elements borrowed from different set genres gel so well together. The Miyazaki self discovery brand of character development is perfect for a 6 episode OVA. It lends itself to a concise story and an ending with plenty of closure. The linear plot threads of self discovery, a few rather straight forward romances, and an alien invasion are developed at an easy to watch pace without many lulls or overloads. Underdogs are naturally inspiring, and it's hard not to be taken by the ebb and flow of Sae's sense of self worth. The melodrama typically found in Shoujo and High School dramas is present, but mellowed out because of the more humorous, and light hearted approach to this OVA. Harem accents might seem like automatic bad blood, but the polar intersection of its ecchi humor and an otherwise "family entertainment" suited story is just amusingly awkward.
As a whole, there's very little wrong with Magic Users Club. It won't likely blow your socks off either, for despite its charm, its characters and plot are still on the simple side. The rest is humorous fun that might have dried up had it been extended to a full TV series, but in its 6 episode state, it remains lightly funny to the end. Magic Users Club is just something that's easy to enjoy and tough to pick at.