Happy New Year to everyone !!
This question is similar to a previous question I posted regarding the number of rewrites generated by the 6.2.1 Optimizer vs the 7.0 Beta one. This one, however, is simply that a SQL statement passed into 6.2.1 generated 413 rewrites - 26 alternatives with unique execution plans and yielded an 87% improvement and yet when the exact same statement is optimized using 7.0, there are no improvements to be found. (Same Intelligence Level - 4)
I understand the issue that was found in 6.2.1 in terms of the number of statements being incorrect, but the above example is going to be very confusing to customers and I feel will ultimately lead to a lot of Support calls.