Peter,
I bought a Rotozip Zipsaw and used it last week for one job. Returned it the next day. Half-@@@ design and very difficult to control in either direction, but pulling towards you offers the best control. I have the RZ2000 with the ZipMate wheel attachment. I thought that a dedicated tool would be faster, easier and better to use --- wrong! The body on the Zipsaw is great, better than cutting with the RZ2000, but the blade guard/housing is crap. All plastic with a plastic locking clamp that doesn't even hold it down tight to the body of the saw. There's no adjustment and it wiggles, so during use, the blade cuts into it. You can't use the blade guard as a straightedge because it wiggles and there's no blade depth adjustment. The Zip Mate attachment for my RZ2000 has a locking metal clamp that works, a blade depth adjustment plate that works and can be used as a straightedge guide while cutting against something. I called Bosch/Rotozip with my usage findings and asked them to try and sell me on keeping the Zipsaw. The guy honestly said he couldn't and agreed with me that it would be best to just keep using the RZ2000 setup. --- That's my personal experience with the tool.
Festool, you got something in the works for your version of Rotozip style tools? Might be a good market segment!