I'd first off start by saying that the 2003 Spurs and 2007 Spurs were almost a wash. While Parker and Manu were better in '07, the same cannot be said about Duncan or Bowen. The 2003 versions of those two players were better than the 2007 versions. The 2003 team was excellent defensively as well. Defensively, the 2003 Spurs allowed 90.4 points per game to 90.1 in 2007. The difference was what they scored: 95.8 in 2003 to 98.5 in 2007. I find that hard to describe as "by far". The 2003 team also finished the regular season with a better record of 60-22 vs. 58-24 in 2007. The 2003 Spurs were also STACKED! Duncan, Robinson, Manu, Parker, Bowen, the Steves: Kerr, Smith, Jackson, Malik Rose, Kevin Willis and Speedy Claxton. Depth was not an issue in San Antonio in 2003.
It's a subjective poll, with the definition of "greatest team" being so very open to interpretation. That's why in my post I said that you couldn't go wrong with choosing either team, but my case led me to the Lakers as being considered "greatest" team. You really can't go wrong picking either, but you have to pick one, so my choice is based on overall results. Defeating the defending three time champs that boasted arguably two of the top ten players of all time, coached by arguably the best coach of all time was HUGE for San Antonio in '03, especially after the complete obliteration the Spurs went through at the hands of the Lakers the previous two years.