I'm sure MCed gals suck when you have a late-game group bunched together, but Espers in particular have never caused me trouble outside base assaults. In one amusing instance, I had a slave soldier along as a substitute and while everyone else was ganging on the Esper inside the ship the slave soldier (since these guys have no stamina) was lagging outside the craft, getting MCed or terrorized and uselessly firing his popgun against the exterior.
As for offense, I still haven't used any Psi-equipment other than the Market wands, TK fist, and Master's Cane. The Hellgun looks interesting if I ever run into Dark Ones again, but I have to ask if there're really any Voodoo-specific magic/weapons that aren't worth less than another gal wielding pretty much anything else?