Every age has produced some heavy weights. And PT era was no exception. Yoda and Mace are specially notable.
However, due to lack of exposure to the constant threat of formidable opponents (e.g. Sith and Mandalorians), the majority of the PT era Jedi put less emphasis on combat and the disaster of Geonosis is one example. Add to this the case of Jango Fett, who managed to kill Jedi even with his bare hands, makes things look even worse for PT era Jedi Order.
In contrast, the Jedi Order of OR not just faced the threat of Mandalorians, they also had to deal with nuemerous Sith invasions. These pressures would ensure survival of the fittest.
Also, the heavy weights of OR were no joke by any means (Sith or Jedi). They accomplished some amazing feats;
1. Sion gained immortality.
2. Nihilus could drain entire planets.
3. Traya could kill Jedi Masters with a wave of her hand.
4. Ancient Sith could cheat death or learned ways to live very long.
5. Exile became death of the Force and defeated 3 notable Sith Lords (mentioned above).
6. Revan (as a Sith) created a Sith Empire and (as a Jedi) played a pivotal role in defeating the Sith Empire he created. His legacy (as a Sith) would again prove to be instrumental in making Sith once again very powerful and the lineage would give rise to Palpatine (the ultimate one).
In addition, SWTOR reveals that some Jedi Masters of those times were very powerful. The SWTOR Hope video presents an example.
So we should give the heavy weights of OR credit whenever due.