@Jono, I loled at that as well. Complete contradiction.
Anyways, some complete rubbish here. First off with the Grace and Armstrongs fitness. It wasn't until the end of their careers that either ballooned, as far as I know and Grace was incredibly fit, especially having to run 4, 5, 6, 7 with no boundaries and then he'd go in and bowl for hours on end, maybe not toward the end, but at him prime he was incredibly fit. So that argument fails spectacularly.
People are right there is no proof about the greatness of Hobbs over Hayden (geez does this really have to be argued?), but we have such a wealth of anecdotal evidence, such an amazing amount of testimony and we know Hayden isn't the most perfect batsman either that the decision doesn't really become a hard one.
And again, the players of today> players of yesterday argument doesn't work because it has another side of the coin. Put a player from today and transport him 70, 80 years ago with no protection, a smaller bat, sticky wickets, no chiro every two seconds, no video analysis, 6 month voyages overseas and let's see how they cope! I feel that cricket then was very much a tougher game so to scoff at that age in comparison to this one is very unfair, to say the least. So as I said, the argument certainly has two sides to it.
Last point and it might be a tad controversial, but I've always felt it - cricket has always been the same. The game, imo, really hasn't changed that much from decade to decade. Fitness and general strength in cricket (as opposed to skill and talent) have never ever been as important as in other sports (football, basketball) and I feel that semi-accurate comparisons (within reason) can be made throughout the ages because the various changes to the game then and now aren't that major.