Only flaw with the argument is that Fed admitted in an interview a couple of days back that his shoulders are stronger and his backhand is better than ever before, so we are actually seeing a prime Federer now. This argument is offset to some extent because he is older and so his eyesight and quickness could have degraded to some extent.
I've done a bit of snooping and Federer stated in some interviews in 2011 that hes as good as he's ever been. So basically Federer is beyond his peakest peak form, and if he grew up in the era of Murray and Berdych he would be ranked #7-#8. All the tournie wins in the weak era gap gave him a mental boost while derailing confidence and momentum in his opponents. If he was Murrays age he'd be a 1 slam wonder with a losing record against older more veteran 6 time slam winner Roddick.