I may be wrong but isn't the one with tracks used mostly for vinyl pools? I have the iRobot Vero 300 (made by Aquabot) which is essentially equivalent to the Turbo T-jet. The Vero only runs for about 90 minutes and then has to be turned on again to run longer. Hopefully the A. Turbo T-jet has a controllable timer. The really nice thing about the Turbo T-Jet is there are many, many, less parts to break or wear out than many of the other Aquabots or other 'bots. I've been using mine for three years. I've replaced only a small plastic strap that secures the power cord inside (I didn't have to disassemble to replace it) and I've had to readjust the cord some as it was pulling on the remaining plastic retainer. My pool surface is pretty rough so I think I'm going to rough up the wheels a bit as they have smoothed out some.
You may not have this situation but I have EXTREME amounts of extremely fine sand and silt year round. The fine silt bag fills up too fast, in my situation, so that the bot doesn't make it up the steep slope to shallow end after the fabric gets clogged. There are very few people, though, that will have anywhere near the amount of silt I have.
Of my three cleaners the "Aquabot" is in the middle when it comes to getting up leaves using the regular mesh bag. The Polaris 280 is the best, with the Tracker 4X (like The Pool Cleaner) the worst but it does the best with fine silt.
gg=alice
