This is my 3rd Timex 100 lap Ironman watch over last 8 years.
The 100 lap function is great for my indoor track running and the water proof is great for my lap swimming.  Two time zone setting is very useful when I travel to a different time zone. The alarm settings (5 of them) are  automatically changed to the new time zone. That is why I kept buying this watch. The first unit stopped working after about 5 or 6 years of usage and a couple battery changes. The second unit had a model change with a simpler and a better style without any functional changes. However, after about 2 years usage, the battery went low and I tried to replace it. The soft plastic broke off the pin hole and the band no longer able to keep attached to the watch. Also the watch lost the sound. The new unit I bought a month ago is exactly the same model and I will bring it to a professional to replace a battery.