The first thing I'm going to say is that I am a fan of Akamatsu-sensei's work and may be a bit biased. Now, the next thing I am going to say is that Xebec did not do "Negima" the justice it deserves. Why? There are several reasons.
For starters, the character designs throw you off right at the get go. Any Akamatsu character, more specifically females, have a sensual feel to them. Xebec's designs lacked that. The cheacters looks stiff and unnatural.
This leads me to my second point, there was no fan service. An story from Ken Akamatsu without fan service is like a cold bowl of ramen, it's just damn disappointing. What's worse is they include Negi's sneezes that reveal Asuna's panties but leave out said panties. When I first saw this I thought it was edited and actually e-mailed Funi to learn it was uncut.
The Japanese dub was very well done. All the girls sounded very natural and like what i imagine a class of Japanese jr high students would sound like. The English dub however, I cannot say the same. No usually I hold Greg Ayres in good standing i believe he did poorly with Negi. He spoke so quietly taht at points i couldn't understand him and the accent sounded ridiculously fake. I couldn't get enough of the opening song though, however I have a bias toward that type of music.
So you may ask yourself why i gave the series an '8' if I had so many quarrels with it. Well, the truth is it was still the story and characters that I love. Also, the ending was done very well, even if the rest of the story wasn't, and proobablly made the overall difference of a '7' and an '8'. The last five or six episodes are a very intense watch.
Overall though it's not hard to see why SHAFT was able to remake the series. I recently saw the trailer for the second version and actually watched two of the OVA's that go along with it. It looks like an improvement so I'm very anxious to see how it turns out. And if nothing else has changed, ladies and gentlemen WE HAVE FAN SERVICE. I give you...Asuna's panties!