6-2 and 6-6 is nothing exceptional (DWill+Brewer, Rip+Stuckey, Nash+Richardson, Evans+Martin all are bigger or roughly the same).
They have prototypical height and very good weight for their position, but what I think is more important is that they may just form one of the most productive backcourts based on last year's stats (Miller had an 18.6 PER while Roy had 24, 42.6 combined).
Granted, Chalmers+Wade combined had a higher PER (44.7) but Chalmers is below average. Parker+Ginobili could be the best (>46) if we don't count that Ginobili didn't start, didn't really play starter's minutes and missed half the season. Hmmm. I think that's it!