Not much without some numbers providing some deviation from a flat response. Neither of these output specs is very useful. The first one is more conservative because it says the output power averages 100W over the audible frequency range. What it doesn't do, as I said above, is to provide deviation numbers. The second one rates power just at 1 KHZ so we don't know whtat the power output is at other frequencies but, most likely, it is less somewhere along the line. I would say the first amp is more powerful but probably not meaningfully so.