I have faith than when complete the resulting
objects will be smaller and faster. It doesn't make much sense
to enquire about "SPEC with -fno-cse-skip-blocks" because it may
be unreasonable to expect all the intermediate steps to be monotonic
improvements. If anything is to get done, we need to take a little
risk once in a while. Indeed early stage 1 is when we should take
those risks.
The nice thing is that we have bugzilla to track regressions. We
can fix missed-optimization regressions from now all the way through
stage 3 of 4.3's release cycle. However, I'd expect 4.3 to benchmark
better than 4.2 once Steven is through.