Finis Tempo Trainer Pro

Anyone else out there use one? What has been your experience with manufacturing quality? I am already on my second unit. The first one lasted for a year when it started to take in moisture and mist up. I put it down to the fact that I had dropped it on the shower floor a few times and figured it had developed hairline cracks. However, prior to it taking on moisture the buttons also started to seize up and I had to push harder and harder in order to get any reaction. My second unit has only lasted a little over three months. I have been extra careful with this one: I haven't dropped it once, always rinse thoroughly after use and have been as gentle as possible when pushing the buttons. Last week, the left button seized completely. I could turn it on, but I couldn't turn it off. Fortunately, it has a saftey feature that ensures that it will turn itself off after four hours if no buttons have been pushed, so it didn't waste too much of the battery power. However, yesterday when I tried to turn it on, it was stuck in the off position. To make matters worse, I notice that the screws in the back are rusting and there is a very small amount of moisture inside the screen! And, no, I have never attempted to open it at all. I train on my own and the pool I train at doesn't have a pace clock. I use my Tempo Trainer mostly on Mode 2 to give me sendoff intervals. It is an invaluable tool and I am completely reliant on it now, however I am loathe to keep on handing out money for something with such unpredictable quality. Anyone else have this experience or has it just been my bad luck? Are there any similar tools on the market that I might consider?