I am looking to drive fairly inefficient speakers such as Martin Logan Prodigies. I am assuming I need a lot of power. Obviously I intend to listen before purchasing, but I would like get educated and help narrow down the choices. I have spoken to some dealers and manufacturers and they all say - "Sure 155 wpc is enough because our amp is specia! Don't worry about the power rating. Our amp has expensive parts ans design and can drive any speaker" Is the power rating alone enough to judge, or are there othe factors such as current delivery, power supply, quality parts that help overcome the lower power rating?