The Canons use flash memory. This is good and not so good. Flash memory is still fairly expensive, archiving the video can be a challenge and the video captured is a highly compressed MPEG2 stream (both the FS10 and FS100 are standard definition only). Since flash memory does not use any motors, the battery lasts a little longer (though you will still want to get an additional rechargeable battery). In the Mac environment, the video files will ned to be converted using StreamClip (a free download from the apple.com downloads area). Whether Macintosh or Windows, the video files are copied over USB - or by using a card reader - onto the computer's hard drive. I do not believe either of these camcorders has an external mic connection or manual audio control. Neither of these camcorders has AV-in - but you may not need it, see the HC96 section.
Compressed video = discarded data = reduced video quality.
I am a miniDV tape camcorder fan because:
1) miniDV tape becomes the archive, so no extra step for copying the video;
2) DV data stream is the least compressed resulting in best available video quality compared to the other available consumer storage media (including flash memory)...
The Sony DCR-HC96 allows for external AV device-in connections. Most camcorders do not allow for this. Some folks want to be able to bridge older analog devices to transfer video (like old VHS, VHS-C, Hi8 or other analog devices). If you don't want to do that, the other thing this is useful for is using a helmetcam. You don't have to use a helmet... The HC96 also has a LANC port which allows connection to an optional wired remote that can come in VERY handy for controlling the record start stop when the camera is tripod mounted - or when the helmet cam is used. I believe the HC96 has the Sony proprietary "Active Interface Shoe" that allows use of Sony products that can take advantage of this connection - certain video lights and external microphones manufactured only by Sony.
The Canon ZR930 is one of the least expensive camcorders with a proper (1/8"; 3.5mm) mic-in jack, but it does not have manual audio control, however. It also does not have a LANC port or AV-in.
To transfer video from a miniDV tape based camcorder, one connects the DV port of the camcorder to the firewire port of the computer usinf a firewire cable. Apple Macintosh computers have had firewire 400 ports standard for nearly ten years. A fire port may be added to a traditional Windows machine - they are generally easy to add if the computer has an available PCI slot or PCMCIA slot (and are cheap, too)... more $ if the laptop has only an available Express slot.
In all 4 cases, the stills will be "OK" - these are camcorders and do video well. They were not built to take stills well. If you want good stills, for less than $200 you can get a Canon PowerShot SD750 or other camera that will take WAY higher resolution stills than any camcorder ever will.