Well its and automated thing. Its not like Bambamugen or Acey actually edit each sprite. They scale up each and the results vary. For example, I only use a few, including Blackheart. To me Blackheart looks pretty good and very 'HD'. This one (based on the shots) is pretty close to perfect (for the style anyway) with the exception of the fists.
On the other hand, some come out very distorted and near unusable. But unless somebody wants to manually scale every sprite up by hand this is the only 'HD' conversion method so far. And best of all, these are based on existing creations (warusaki3, Rajaa, etc) so its not like you can't get them normally.
April Fools