From what i've experienced/hear stealth injection will net you a decent profit on a throw away account if used properly. i.e regular break times, don't bot in hotspot areas etc. But mirror mode would probably double the time taken to receive a ban if not longer. Bare in mind it's all subject to change so every individual case will vary. Mirror mode uses the osrs client and runs through that. So to jagex you're using their client which obviously reduces ban rates.