Because EPIC is an individual fiber coating and not a barrier film coating or impregnation that blocks the weave of the fabric, EPIC actually works better in tents and in sleeping bags than it does in rain/wind wear. This is because capillary action can draw moisture throught the pores of EPIC's weave when the material comes in contact with other objects. EPIC coats first leak notably at pack straps for instance. Of course, since most people don't seal their seams, EPIC coats usually leak at seams before the fabric experiences breakthrough.
Tents and to a lessor extant the shells of sleeping bags hold the fabric where capillary action is reduced. Just stay away from the walls when it is raining. EPIC over polyester insulation, as in Golite's Belay jacket seem remarkably waterproof. Water pressure can overwhelm EPIC tents as in a severe downpour, and long soakings can eventually also lead to breakthrough. Many people haven't found it to be a problem in Black Diamond's tents; it's a trade off between bulletproof versus good enough. If you expect bombproof you may be disappointed with a few managable leaks. This might not be a problem for brief afternoon mountain thunderstorm protection, but could be a deal killer for outings with days of continuous rain.
EPIC doesn't breath as well as DWR treated nylons, but it breaths well enough that polyester clothing that gets wet underneath it will dry under body heat in dry alpine conditions.
Unless you really swet up a storm in a sleeping bag, EPIC should only be a problem in retaining moisture under conditions where one could successfully use a vapor barrier liner (under say 10 degrees F). Remember a sleeping bag has considerable area for vapor transmission, so that application really doesn't compare to your jacket.
EPIC does crap out when it gets dirty and it should not be laundered in detergent or with fabric softeners, or it will lose its repellency until those contaminant residues can be cleaned and rinsed out, with fabric softener being the tougher of the two to fix.
You might want to try sealing the inside seams of your EPIC jacket with Silnet or thinned silicone caulk. Once done you may find that the fabric even when it wets through passes very little moisture compared to seam leaks.