a diadem would kill a custom imp. its got break beam eyes, great manufacturing quality, is faster. go to www.actionmarkers.com
and check out all the diadem videos, easily better than an imp, and the price is 600 for eyes and a vert reg, which is what it would be around for a stock imp with just that, the diadem is a much better buy. and i believe it gets better efficiency than an imp. to get a toxic impulse with vision (reflective eyes) and a fade ano (diadems come stock with one) it costs 1050, thats a lot more, and plus the diadem is lighter.