Alexis is awesome. Period.
I don't know why she gets so much bashing. She's one of the best characters on the show. She's real cool and strong female lead that could really hold her own in a duel and has been able to duel her way around any other female character in the series thus far, even Mai and Ishizu, and also several male characters. Yubel may be the only female duelist that's better than her.
True, her role in the series may have diminished a bit since the first couple seasons, but that's because new characters and events were occurring that did not involve her, so she wasn't in it as much as before. All the same, she was cool, smart, strategic, and a great duelist, not to mention very beautiful.