How could this thread be only three pages long?? O_o
Kyle Rayner really stepped up in Hal's stead, proved his worth to the JLA, impressed friggan BATMAN who doesn't impress easy, single handedly cleaned up Hal's mess by reviving the Corps...
And Kyle managed to stand up to depowered Parallax for a bit, looking more impressive than a JLA team including Superman or Martian Manhunter. AND, he actually stopped Hal from powering back up by destroying Oa.
Not to mention the famous bottling up a sun going super nova feat.
And those were all Rookie feats, with no training and no ring computer. Unless his will is in the gutter because of yet another girlfriend getting killed, I think Kyle can stand against Hal, and win.