No, they tend to last really well. They are more prone to breaking than not having them. I've not heard of the torsion bar being more prone to breaking than omega springs in a benchmade, as another reference point. The springs in folding knives tend to last a long time, often longer than the owner. This is also dependant on how much you use one but they're designed to be used a lot and are not delicate.
I think more often the case is the torsion bar getting a little loose and it can make a little noise in the handle due to manufacturing tolerances. I find this to be more the case with the Chinese kershaws. But, this is more of a nuisance than a functional issue.
As a mildly similar design without the assist, maybe look at the civivi hadros if you're leary of the speed assist mech in the kershaw.