A lot has changed since 4.03 though. And BAP project experience confirms there is a huge performance boost for non-trivial code - [ANN] BAP 2.1.0 Release - #9 by ivg :
Speaking of the numbers, I am seeing improvements between 10% and 30% that are mostly coming from significantly reduced pressure on the garbage collector.
OK, so after recompiling everything with -O3, I’ve got about 40% improvement in such simple task as binary disassembling, which is fantastic, nearly twice as fast. On more complex benchmarks the results are less impressive, something between 10% to 20%.