Just for instance the 5000 series cameras before these (the "9000" series), Logitech has generated a camera that thumps out superb video (this one's video surpasses the 5000 series, the ones were better than the 4000 series).
However, it, not enough control, and enormous pile of bloatware that gets installed in the camera, including its enormous system resource demands, choose this another clunker.

Environment:
P4 2.4 GHz processor
Windows XP Pro SP 2
DirectX 9c
USB 2.0

First, favorable:
Color and image quality are outstanding (although focus just isn't good more about this below). The ultra modern support for large quasi hi def picture sizes produces amazing images.

Now, unhealthy:

Machine resources:

You better have a very good FAST machine. And I mean FAST, similar to a Core 2 Duo, or no way. A fairly easy 320x240 capture/preview (not writing it to disk) sucks down 10% more CPU using a P4 2.4 GHz machine with Windows XP Pro, compared to the old 4000 series cameras did.

Holy cow a 2 way 30 fps 352x288 video conference together with the older 4000 series camera would use 55% CPU on my test machine. Within this camera, it comes down to 80% which is with auto focus, auto white balance, auto everything switched off and not just while using the audio from you.

This is usually the 5000. And just like the 5000 series, once THIS camera's driver happens to be installed, including the older 4000 Logitech camera now uses CPU for instance a pig (this thing overwrites DLLs which the older cameras also use).

I've been down this road before. The only way to result in the older camera work efficiently again will be to completely uninstall this thing, and reinstall the earlier driver.


Support for other applications:

I only test these cameras using Amcap and Vidcap32 (the ubiquitous, standard, simple, generic Windows capture apps) and our own custom written videoconferencing code we wrote myself. Thus i don't have anything to say about Skype, IM, etc.

Just much like the 5000 series before this one, this camera DOES support the right DirectX interfaces. Anytime Skype or some other sort of app is freaking out upon you, this is not this camera's fault. Its Skype, or whatever app you might be running. My code works correctly to it.

But... just as the 5000 series, in case you install the "driver only" (to spare yourself the bloatware), half the camera's functions will probably be broken.
When I installed it driver only, it is only do about 10 fps, in a different variety of light, with any picture size, regardless how I set it.
After I installed their obnoxious applications, it snapped into condition and would obey settings in order to do 30 fps.

Bloatware:
It installs services and many auto startup bits of junk you need to seek out inside the "Run" folder within the registry and delete. Otherwise, every single time you log in, you will get these matters running, and therefore the tray icon app, and 2 other apps, can be running. No matter what you are doing, these will invariably restart if you ditch them from registry and also the services control panels.

Their apps also "phone home" to Logitech periodically, registering your purchase and checking for updates. (Yes, dealing, I sniffed the network traffic.) If you don't mind Microsoft and Logitech spying with you and connecting anyone to machines without you even knowing it, fine. Personally, I discover behavior deplorable.

If you're programmer (like me), you can aquire rid of this junk. If not, you happen to be stuck with these things hogging down your machine constantly.

Focus:

The auto focus function works, but overall, this camera's focus is poor. Whether on auto or manual, it wouldn't focus well on objects that get even more than about 2 feet away from the camera. They probably honed the focussing algorithm expecting that you be sitting close to the camera. Of your reasonable assumption, but it's too close focussing. Even sitting within a normal distance in a PC monitor, it cannot focus sharply on my face. It also has AWFUL focussing with the edges of the picture whichever.

Conclusion:
Great video, but poor focus.

If you will be just a usual user who plugs junk into their PC and even know what CPU usage is, and you're simply with a hot fast Core 2 Duo processor, this camera do a very good task for you, so long as you don't sit beyond the boundary back from you.
If you already let Microsoft spy giving you using their automatic junk started up constantly, then chances are you won't mind Logitech doing that in your direction to.

(We do hope you like Windows Media Player opening ports in your house router without indicating didn't know they did that, eh?)