As a Yankees fan, I do plenty of watching.
I love Sabathia, being the workhorse he is. Saying that, Sabathia has seen a consistent decline in MPH, K/9. Since pitchers on average tend to peak sooner than hitters, Sabathia will notice a steady decline in K's. He might continue to put up big W's, and a good enough ERA. But the trends are against him for upcoming years.
Teixeira is a nutcase, but a brilliant talent. He continues to hit into the shift, even though he clearly has the potential of driving the ball the other way. He is only 30 and has several years left of BIG power numbers. He has always shown the ability to float around .300 BA, and has a high OPS/OBP potential. As he ages, and starts DH'ing more, he should continue production and will float around the .300 mark because he is a switch hitter and is a Great pure hitter from the right side.
Only the winner can go to dinner...