The Imagination Station early readers

I just found a new book series.  They are supposed to be like Magic Tree House books, but with a Christian worldview.  They are from the creators of Adentures in Odyssey.   Titles incude: Revenge of the Red Knight, Peril in the Palace, Voyage with the Vikings, Attack at the Arena.  The book website is http://www.theimaginationstation.com.  The flyer I have came in my shipment from http://www.christianbook.com.  Their price is 12.96 for all four by calling 1-800-christian and using catalogue key code 339475 and CBD stock #999903.  Price good to 8/31/11.  Website price was 14.99.  If anyone finds a better price let us know.  I am planning to buy these. 

Has anyone read them and have an opinion on them?