I have seen one used on the web indicating 170 watts per channel. Everything from Marantz says its 150 watts per channel. Is this a case of someone "pumping" up the wattage or are there different models out there?? Also, assuming its 150 watts, would that be a noticeble difference from say 125 watts or do you need to get up to 200 watts plus to notice a difference from 125 watts a channel? Thanks.