I have not driven the new ZIPZaps, without Propo..
for my tracks at home you need to have prop steering and throttle.
I can see maybe the interest died down, but why not carry them anymore, I know lots of people who are buying them on Ebay...
The SE might have had some issues, but anything with 04 or newer date, have VERY little issues.... So I would say most of the issues have been worked out and then they decide to drop the line.