System: Merlin Magix 2.0

I've been reading the forums on possibilities for cordess phone for Merlin Magix. From what I can gather, none of the TransTalk phones are worthwhile, especially when you consider the costs. I've looked at the EnGenius DuraFon and the Plantronic CS55, and the seem pretty good. My questions is does anyone have any experience with these phones in a warehouse environment of about 300,000 square feet? I know that the DuraFon claims to work in 250,000 square feet and 12 floors in building, but has anyone used these phone a similar environment?

Thanks.