Slipper,
If you still haven't decided, you might want to take a look at
http://www.dvspot.com.
Jeff Keller runs the site and has reviews of the ZR series as well as the TVR series.
The Canon's 18-22x zoom is the best feature of the Canon's. The only problem is that the CCD is rather small. Somewhere in the region of 340,000 pixels. The Sony 19 and 22 also use a small CCD, but the TVR33 uses a better CCD (600,000 pixels). This apparently makes a big difference. The only thing is that the TRV33 retails for about $100 more than the ZR70.
You have to weigh all the options and models to meet your own needs.