Get used to seeing creosote inside your OWB. In most OWBs the smoke and water in the firebox continuously condenses on the sides of the surrounding cooler water tank. As a result creosote builds up. Also the type of wood makes a big difference. Burning pine or fir with a lot of pitch will result in more creosote buildup. Burning a hardwood like maple or oak usually results in less buildup. Burning green and wet wood will result in more wet gooey creosote. Burning dry hardwood will result in less dry flakey creosote. The water temperature setting will not really make a huge difference in creosote buildup, because the firebox is a lot hotter than the surrounding water jacket. You will always have condensation on the sides of the tank, even when set to 195 F (which is about as hot as you can go before you start to get boil-overs). In most starved-air OWB systems (I am not familiar with your brand) just scrape down the sides and the creosote will burn in the fire. I use a garden hoe and a flat shovel to do the job every few days, more or less often depending on the wood I am burning. We have been running a Central Boiler OWB unit here for 3 years now, and love it.
