disadvantages of IS?

I now have two IS lenses and the only downside I can see is that on a long'ish' lens like the 70-200 the battery drain is much higher than my 17-85.

dipps wrote in post #8996670
only real disadvantage i can think of is possible failure (17-55 2.8 EF-S seems to have issues with IS ckt failure). i could be mistaken, but i had also gotten the impression that at least some lenses need to have their IS ckt turned off if being used on a tripod. i'm not sure what the repercussions are on images if you forget to turn off IS with these lenses while using a tripod.

I have a 17-55 that had an IS failure. I paid canon service center $95 to have it fixed.

the more wimpy folks also think IS adds extra 'weight'...

In all seriousness, I wish my 17-55 didn't have IS. I am a fan of simpler, more robust and enduring designs. It sort of seems designed to break-I say that simply because it's such a complex electronic system, but also due to all the reports of IS failure. The other thing is I feel like I simply don't need IS on a lens of that focal range because I like shutter speeds of at least 1/250 or so just to keep subject blur to a minimum. This is far greater than the necessary speed of 1/90 or so at 55mm to avoid blur due to camera shake. I know that you can come up with many scenarios where IS is really helpful, but maybe I just don't shoot as much in those situations. Another silly thing is that I feel a little skeezed out by the fact that one of the elements/group of elements/whatever you call it is not anchored. Just feels a little sloppy/unpredictable to me.
On the other hand, it's pretty cool to have it on the 70-200.
My two cents.

In these days of amazing battery performance , it's a lot less noticeable, but if you'd asked this same question in 2004,. there would have been a page of answers saying "reduced battery life" as the only down side...

It's well worth the trade off