Wattage output can, and is, misleading at times. It depends, in part, on the ohm rating that you run your speakers at. and what exactly are they referring too. Look at the output per channel. I wouldn't be too concerned about that. What I noticed about the Panasonic is that it has an integrated blu-ray player. That usually means that the sub-woofer is passive as it derives it's power from the blu-ray player. That, in turn, will affect how efficient the sub is, and you probably won't get that really nice bass that sounds so good because it doesn't have its own amplifier (active sub-woofer). Also, the speaker connections may not be universal (5-way binding posts) so you're kinda stuck with the speakers if you want to upgrade them down the road unless you're good at splicing wires and making connectors. The Yamaha, OTOH, does not have an integrated blu-ray player and thus the sub-woofer is active (meaning it has it's own amplifier) and, if that model of Yamaha is like mine, has binding posts on the back so any future speaker upgrade won't be an issue. I run mine at 8 ohms which gives me 80W per channel which is plenty enough for me.