The Spurs' 11 game winning streak was snapped in their last game, and the Lakers went on a 10 game winning streak before losing to Portland and have since started a new streak with three straight wins, including a 37-point blowout of the Clippers.
There is a huge difference between these two winning streaks: the Lakers won their games by an average of 17.1 ppg, while the Spurs won by only 3.3 ppg. Both teams have played sub-.500 teams in most of their games during the streaks.
If these teams go head-to-head then I would take the Lakers any day because since losing to Portland, they have stepped up their game on the defensive end to a completely higher level. Although it might not have been there for the full 48 minutes against Sacramento, they held them scoreless through five minutes in the 4th quarter.
Since LA is second in the league in scoring at 110.9 ppg, they can also score the ball very easily and have the best scorer on the planet in Kobe Bryant.
This separates them from the Spurs, because while the Spurs are a great defensive team, they would have a really hard time keeping the Lakers below 100 points in a game. I don't remember the last time the Spurs scored 100 points, so come playoff time, don't be surprised if the Lakers beat the Spurs in the Western Conference finals.
If you like to compare the two a little deeper then look at the history of the coaches in the playoffs since 2001 phil jackson is 14-6 in the playoffs against gregg popovich and then you can look at the benches even though the spurs bench has more points coming from their bench that would be because manu ginnobli comes off their bench but the lakers have guys like vujacic,farmar,radmanivic,walton,ariza,mbenga,mihm,turiaf who can all produce at a high level and can build on leads and the character of the leaders kobe and duncan duncan is a great leader but kobe is just a bit better because he is hungrier right now then duncan and when kobe uses his will he will not be denied even by bowens defense so the lakers should be the winners over SA