The sight glass goes into the bells and whistles category. It’s pretty much a one shot thing that can be done with a dowel with number on it. The thermometer is something I wouldn’t be without for both chilling and approaching boil temperature. I use the lid to get to boiling quicker, but use that time to start clean up. It's nice to be able to glance over and see how close it's getting without taking the lid off. Or having the mess of a boil over.