Has anyone used Zact?

I am a current Sprint subscriber, and I am very frustrated with the poor quality of the service. 75% of my calls get dropped, and this has been going on for 2-3 months. I am out of patience with this premium provider. I am considering Zact. The coverage map seems almost too good to be true. Has anyone had any experience with this provider? If this isn't some type of scam, it almost seems like a no brainer since they have a 30 day return policy. Has anyone had any experience with Zact, or are

there any unbiased ratings on this or the other discount prepaid providers?

via Forums de téléphone cellulaire (en français) http://cellphoneforums.net/fr/general-service-provider-forum/t365091-has-anyone-used-zact.html