John,

Thanks for that.

I've had the Ferm for a few years but I certainly wouldn't describe it as
being in any way crude, so perhaps I was lucky and missed the earliest
incarnation.

The locking-orientation chuck sounds like a good refinement but since most
of the use I have for the tool is demolition than channel-cutting I think
it's something I can live without. And while the Ferm is certainly weighty
I've not found that a particular inconvenience.

The speed control does sound desirable though, as do the other improvements.