Comparing free online vs $50/year for Live, is just not a valid point. There are many who do not play online, so it doesnt make a difference to them.
At this moment, game developers who have been developing games for these consoles for the past few years, have admitted that they are still unable to unlock the true power of the PS3. I dun think some story writer can decode the Cell processor, unless he is some engineer who had many years of CPU architecture and designing experience. Since IBM is the developer for both CPU, email and ask them which is the most powerful.