Steve has much to say of the Neo Magnet 6 inch Lowther here on the web site. But after reading the following sonic difference description between Alnico and Neodymium at Jon Ver Halen's Lowther-America site http://www.lowther-america.com/Drivers  I think I would prefer Alnico.

Alnico Magnets
The stiff magnetic field of Alnico allows the driver to reproduce a great deal of the harmonic development of instruments and voices - information that makes them sound more real. This information can be described as extremely low level information, the "texture" of the sound. Lovers of vocals, orchestral, and other forms of rich music sound generally prefer Alnico drivers.

Neodymium Magnets
Neodymium is extremely powerful for its weight. The sound of these drivers is extremely fast, with lightning transient response. They also have a big and bold flavor to them. People who listen to rock, jazz and other forms of "exciting" music tend to prefer these drivers.

I have Google searched for reviews of the A45 and A55 but have found only this one http://www.dagogo.com/a-flight-of-lowthers.
Has someone here on this forum tried either of these speakers? Or preferably both as I would like some help choosing between them.  
Have you come across a review you could point me to?