Python vs Meridian Auto Water Changer

I need a water changer but have never seen one. References have been 
made in APD to the PYTHON.  I was about to order one when I received a 
well done three page brochure from Aquarium Products describing their 
"Meridian Automatic Aquarium Water Changer".
I would dearly love to see the two products side by side but 
unfortunately the local shops have neither.  Does anyone have  
information and/or recommendations on one or both to help me make a 

Jack Blumenthal