Steve, a gallon of wort does take a while to boil down. I only started with a half gallon and it took about 20 or 30 minutes. While the wort does give you some indication of its status, I do like using my RT600C thermometer to monitor the wort temperature closely at the end. I think the temperature target is actually like 320F (I'm apparently dyslexic based on my post above) and it would be a shame to burn it needlessly. The temperature does shoot up pretty quickly at the end, so the monitoring is necessary to avoid scorching.