As far as the power bobtach goes. I thought it would be nothing but trouble when we got a machine with that option. My thoughts were the hoses would get caught on something and get torn off. It never happened over the 8 yrs of hard use. But you must keep the pins lubed up or it will give you trouble. When I say lube, I don't mean only grease. Pouring motor oil (new or used) directly on the pins is a saving grace. For some reason oil will work on a stuck pin when grease wont. The foam tires will bust your back, not only trying to lift one up but when operating the machine. I would lose them, they are hard on drive chains too. The keyless entry on the machines we have had, never gave us any trouble at all. In fact its kind of nice knowing not every key made will fit your machine. And you can program your own code for starting. As long as you are popping the hood, you could check the case drain filters for debris. They aren't too hard to access. Also if you haven't already, check the chain case for fluid level, and milky colored oil. A 160 would be a nice upgrade from your 743, I understand the whole computer thing can be intimidating. Especially coming from a 743b with a track record of great reliability. But those little black boxes can be useful at the same time. If you do end up buying the machine, post pictures, good luck