A recent survey by Square Trade has found out that there is a 82% increase in broken screens for iPhone 4 compared to the iPhone 3GS. The survey also shows that an iPhone 4 owner is 64% more likely to have an accident with it than the owners of an iPhone 3GS.
Cracked and broken screens account for the vast majority of iPhone accidents. Screen damage is responsible for more than four-fifths of reported iPhone 4 accidents, slightly higher than for the iPhone 3gs:
Multiplying the accident rate with the cracked screen distribution, we find that 3.9% of iPhone 4 owners reported a cracked screen within 4 months, as opposed to just 2.1% of iPhone 3gs owners. Square Trade also predicted that 15.5% accident rate by 12 months, which is double of the iPhone 3GS, shown in this graph.
Overall this shows that the iPhone 4 is more prone to physical damage than the iPhone 3GS. The aluminosilicate glass seems to crack at least as often as the old glass and there is now twice as much surface area to break. Despite this, the iPhone 4 is still a well constructed product with non accidental malfunctions a lot lower than other electronic products.
[Via Square Trade]