I think the thing you need to be more concerned about is the efficiency of your speakers. Keep in mind that the sound level doubles every 10 db, but the wattage needs to increase TENFOLD in order to double the sound output level.

Before you get alarmed though, go back to the efficiency of your speakers. If your speakers have an efficiency rating of 90 db (most speakers are in the 85-90 db efficiency range), that means that it takes ONE WATT to get those speakers up to 90 decibels, which is very loud.

If you're using the same speakers, then yes both amps are outputing the same wattage to achieve the same volume level.