After using both, it would be a great tool if they could be blended.
The SS is light with its plastic, easy to handle, fits in the hand. The lock doesn't really work well.
The HK works great with the teflon
glide, apparently teflon is going to be getting scarce however. The holes in the tool make for cleaning any fabric safely. The way the water works over the fabric in the HK tool really flushes it well.
If I were going to make a tool, light weight but sturdy.
Ergonomic, easy to use, get into corners, get along edges
Uses holes rather than a slot
Doesn't "need" to operate at TM pressure but nice if it can handle it,
at least 3" wide
Uses a jet, not freeflow
Little to no overspray
basically, I'd build a HK tool into a SS body, with a few mods