First of all, could you describe the seasons, conditions, and geographic location where you would be using such a shelter?
Given all the venting options possible for a pyramid style tent, I don't think that a W/B material is necessary for this kind of shelter. Instead I would go for a lighter material--possibly even Cuben (see http://www.ryanjordan.com/2006_arctic/2006/06/ultralight_shel.html). A spinnaker nylon material could also be considered. A 'Mid made of Epic or eVENT, I don't think, would outperform a stock BD Megalight or Golite Hex made of SilNylon. I incidentally have often used the Megalight for Winter camping.
I have a couple of Epic tents---both by Black Diamond, a Firstlight and a Lighthouse----they are superbly light (Epic is the lightest W/B material found in use for shelters) and strong high mtn. tents that I have used in the Sierra, Cascades, and various Canadien Ranges in all seasons. They have performed well in keeping me dry because, in part because I keep the Epic clean (when dirty it leaks). Condensation has been low for multiple reasons--- the material, itself, where I pitch my tent, and making use of cross ventilation. The tents themselves have weathered sharp outbursts of precip and generally have exceeded the manufacturer's reccomendations. Experiences will vary. Some individuals have had experiences where they experienced wet out far earlier than I have. The epic material, from some accounts, doesn't perform so well in lower elevation, higher humidity and higher temperature environments.
There will continue to be this siren song about Epic----it's extremely high water resistant nature will last the life of the material. It won't wear out, delaminate or peel off or become contaminated by body oils. Contamination by dirt will cause it to leak----wipe it clean and it's original performance returns.
Hope this helps.