Hi,
I think first one is better since it is consuming less number of lines also.
Also with the help of standard tcode ST05 you can trace your program also by seeing which is consuming and how much time.
And also you can follow below steps to see your program performance.
STEPS:
1.OPEN UR REPORT IN SE38 TRANSACTION.
2.SELECT THE MENU PATH
UTILITIES-->MORE UTILITIES-->RUNTIME ANALYSIS
3.SELECT THE PROGRAM RADIO BUTTON AND GIVE UR REPORT NAME THERE.AND CLICK <b>EXECUTE</b> BUTTON
4.IT WILL TAKE U TO ANOTHER SCREEN THERE U CAN EXECUTE UR REPORT AND COME BACK.
5.CLICK ON ANALYZE BUTTON.(PRESENT IN BELOW OF THE SCREEN).
THEN U WILL GET ONE GRAPH
NOTE:
1.IF IT IS RED UR PROGRAM IS HAVING VERY POOR PERFORMANCE
2.IF IT IS GREEN IT IS OK.
ABAP GRAPH : TELLS UR CODING IN THE REPORT.
DATABASE GRAPH : U R RETREIVE DATA FROM DATABASE IN UR REPORT..
Sumeet