Janine, how has your experience been with this one?
My experience was good, but it was limited to one afternoon. I did brew many teas that day, and I used this pot over and over again. Sometimes it was very full, sometimes not. Then again, I'd imagine boiling time does depend on the amount of water as well. I did not note exactly how much water these kettles held, but I'd guess maybe 2 liters? maybe 1.5? (Don't quote me.) They were a very convenient size, not too big, not too small. It seemed to work very efficiently. It was as interesting watching the temperature gauge fall (and how fast that happened) between brews as it was noting the water temperature through the boiling and steeping process. It at least gave me a good idea of what exactly was happening with the water - its properties, how it cooled, how long it took to cool as it sat, or heat as it warmed, and what exactly I was pouring.
I don't generally (personally) value being absolutely scientific about these things. Once upon a time, a former manager at Imperial Tea told me that there is a very important traditional part of tea that values brewing via experience, being in that moment - over let's say having a timer and thermometer, and I think he was right. But it was really interesting to have that kettle to use; and especially so if one wants to really evaluate what happens at different temperatures. BTW that same teacher also taught me to use different temps to brew different teas, but to tell by the steam escaping from the kettle or simply by feel.