Any reason to? Any real reason not to?

pros: keeps crap off the mic

keeps the mic a bit more 'safe'

makes the mic a little more visible.

Looks sexy sometimes.

Keeps lipstick off the mic


Cons: anything brushing against it can make a horrendous noise, just like outdoors but it's more likely in an enclosed area.

Some people like to touch squishy things.


impact on overall sound? None if it's a good screen.

Thanks, Douglas.
So would you think I could feel confident that
windscreens offerred by companies such as
Sennheiser, Audio Technica, and Rode
would be "transparent".

Manufacturer-supplied foam screens should be fairly transparent (although they may not be very effective in wind). All screens will attenuate some frequencies to some degree. The best way for you to judge your screen's impact is to simply test it by setting it up on a stand and recording someone reading a passage of text with and without the screen.

Such an experiment will help you judge whether or not to leave the screen on the mic at all times for sonic continuity. Personally, I prefer to keep a screen mounted on my shotguns at all times, principally for bash protection.

I get pretty fed up with the average manufacturer-supplied windscreens for vocal, stand and instrument mics. They are usually too thin, and worse, they are usually too small to effectively cover the rear of the mic's grill area.
They are designed for maximum transparency and protecting from breath pops from the front only. If you are doing anything with the mic other than using it in the studio at 6 inches or greater distance, the stock screen usually isn't sufficient.
I usually get slightly thicker and larger generic screens to use for indoor booming or outdoor light-breeze protection.
With the addition of a black no-metal, no-exposed-rubber hairband, they stay in place very well. They are also much easier to install and remove.
In addition, this hairband makes the over-sized foam poof out a little to form an air gap around the head of the mic. This greatly enhances the ability to stop noises from swinging the boom or a light breeze.
Under most recording conditions that would require wind protection in the first place, the sonic difference is minimal.
As mentioned you should test it out for your particular conditions.

Yeah, I will test and get back with the results.
I have done testing with furries, and they seem
to attenuate the upper frequencies.

Don't forget that the foam windscreens and fuzzy covers make great toys for Police Dogs. They think it is their 'reward' toy. Let's you get great pictures of a large dog lunging for the camera.

Anybody need a slightly chewed microphone?

Seriously, a foam screen on a boomed microphone can kill the slight wind noise caused by moving the boom to follow the action. It also works well for the errant breeze caused by air conditioning, etc.

Because I work with a lot of students, I keep the shotgun in the full zepplin when shooting their activities. Saves on shotgun dents and motion-induced wind noise.

For voice work, I don't think the fuzzy covers have much effect do they?