This really does typify everything that Canon seems to enjoy doing. After the length of time I've spent investigating what it takes to get Canon scanners working at all, it seems that Canon is trying to either go out of business or make people dependent upon lazily-written software. I've not enjoyed the struggle to get any Canon scanner working on any platform.
1) Frameworks: Emphasis on "works." BOTH Microsoft Windows and Mac OS X have frameworks in place to allow hardware vendors to write implementation software for their hardware, and most companies will use this method. Canon feels it must reinvent everything with their driver/kit method. With most other vendors, I plug in a device, Windows recognizes it as different, loads the software, and sometimes you have to restart. On OS X, you install the bundle/plugin/extension, restart the system or the application, and the new hardware will work when you plug it in. Which bring up another point.
2) Installers: BOTH Microsoft Windows and Mac OS X have installer applications (MSI and Installer, respectively). WHY does Canon feel that it has to reinvent this as well?! I use the OS I trust (enough), as do most people. A complicated, non-system-standard "installer" means more of a chance to a) break something that the system standard installer wouldn't and b) break something when the custom uninstaller is used. Also, using a custom installer gives the impression that they're hiding what they're doing. For the most part, one can examine the Windows registry in one specific location to see what was done, and on OS X I find that a perusal of /Library/Receipts/Software.pkg/Contents/Archive.bom shows me everything that was installed when I installed "Software". The Canon installer seems to be "puttin' stuff someplace".
3) Toolbox X + Driver Y = Z: What's the latest Toolbox? I had to come to MacUpdate to find that out. Canon doesn't mention it anymore. What's the latest driver? That's up for debate as well if you look around on the message boards. What's the most stable driver? Nobody really knows. So when "Z" doesn't work, was it the driver, or the toolbox?
Everything I've mentioned is why most applications can operate interactively, be independently upgraded, and continue to work... sometimes better than before. It also puts the onus of poor operation onto a specific system component that can be troubleshot and corrected. Without that, people are going to blame the least-compliant element of the equation, and it looks like it's Canon here.
Hey Canon! How about developing software that's installed with the system-standard installer to get deployed into the system's common framework so that any properly-written application for the target OS can tap into said framework and gain uniform access to resources? Yeah, too easy, useful, and acceptable, I'd bet.
As far as my review goes, I give the software below average features, because it's worthless without the driver.
Ease of use I'm gauging against other software I've used, and this has to be some of the worst: track down the right driver and the right toolkit, install them both, hope they work, and configure the plugins to be installed into the applications that Canon has deigned to grace with support.
Value, same as above.
Stability: Well... it IS stable. Above average there, compared to some other applications.
Despite the appearance that my ratings of not-all-1s gives, I'm still not supporting this software. I'm just trying to put an objective bent on what I've said, and anyone is welcome do agree or disagree as they see fit.