and yet if you compare him to today's top players he was mediocre
No he is NOT. Gonzo in AO'07 was better than Murray in AO'11 and '10, Nadal W'11, Berdych W'11....
Did you see how he was playing back then? His FH has a guillotine and he would have eaten Murray or Berdych alive. And btb, he dismissed Nadal in straights and made like 2 or 3 UEs in the semi during that run. Show me how today's top players are better