Difference in using BI 7.0 and BW 3x in SCM 5.0

Hi,

SCM 5.0 comes with BI 7.0 (SP9). I heard the BI system is unstable until SP 14. The question is does it make any difference using BI 7.0 and using BW3x, which is also option BI 7.0 gives with the transaction RSA1OLD.

Thank you.