Hi Elias,
It appears I screwed up my previous benchmark of SIEVE. I apparently forgot I had the XTerm on my desktop logged into an instance of Ubuntu Server LTS on Amazon Web Services, and ended up comparing APL2 on my desktop with GNU APL on a much faster processor.
I've built SVN 669 on my Dell Dimension 2400, an older slower 32 bit machine,
and now get the following results on that box for SIEVE 100000. 4.219 seconds for APL2, and 812.4 seconds for GNU APL.
So GNU APL is about 192.557 times as slow. There's a bit of variability in the time for GNU APL. If I put my ear to the box, I can hear the disk being flogged on, and Task Manager shows the memory bouncing around between 8 and 10 meg rapidly, so it's not necessarily true that the processor time is equal to the wall clock time.
I'm not sure how much time you'll get back by reducing redundant array copying. Any commercial APL will special-case "reshape", "and", and :"index of" on packed boolean vectors, and this is always going to beat GNU APL's object-oriented approach of boxing everything and making no assumptions about the types of values.
Looking back over the bug list, I see only two unresolved issues. Building shared libraries under Cygwin/Windows, and specification sometimes giving the wrong answer when you combine mixed structural primitives with bracket selection.
The shared library thing is important, because with AP210 not being completely implemented, Windows users currently have no way to get ASCII files in and out of their workspace.
Regards,
Mike