That the levers pivot inward, the direction that a fall down produces, means that very little bending of the levers happen. My years of servicing bikes bears this out. I see far more fixed pivot (non brifter) levers with bent in levers then STI ones. I've seen PLENTY of scuffed up, rotated in on the bars, lost/loose end caps but very few issues with the actual internal shift or brake functions. In this respect I consider the Shimano STI to be pretty durable. They do like, as I mentioned, periodic cable replacement and as others have alluded to, lube refreshment.

Now the SRAM double tap levers are FAR more breakage prone. In the few years they have been around I've seen maybe a dozen with cracked/broken bodies. The good thing is that SRAM has a pretty liberal replacement policy. They need to for customer acceptance.

I've seen a few Campy levers with broken bodies, but very few. And Campy parts are quite available either as new replacements or from Ebayed old levers. You'll even see worn/broken Campy Ergo for sale because the seller knows that someone else can and will be able to rebuild them or use the still good parts.

Ben- Depending on how you ride and feel about things like cadence you might find brifters to be only interesting and rather involved to deal with. But if you're like the vast majority of riders I think you'll really like the ability to shift with less effort. As you increase the cog count the inclusion of indexing will have it's advantage too. Andy.