bought this at a student's suggestion to illustrate materiality in evangelical culture (he had experience in "performing" the cube). I'd never heard of it, nor have any of my colleagues. From a scriptural or theological point of view it's completely weird, but it's also fascinating and fun and will remain a central part of my "materiality" classes from now on. Not sure how long it would last "in the field," though.
Use the Evangecube with your neighbors in the States, but leave it out of your suitcase when youre packing for your next mission trip. The Evangecube works well as a visual aid for illustrating the Gospel. However, in developing countries indigenous/animistic people naturally believe that such objects contain power-dispensing spirits. The idea of an object as a simple visual aid and nothing more is utterly beyond their experience or comprehension. So while Western Christians see the Message explained in a concrete, visual way, animists nearly always mix the message and the medium with disastrous results which (sadly) are seldom obvious to us.
My husband has used this for evangelism on the mission field, and is using it to teach others how to present the gospel. It holds the attention of listeners and makes a clear and effective presentation of the gospel.