I have the 25L Klarstein kettle and on balance, I'd say it was good value for money. Apart from the fact that I should have ordered a larger one, the only problem I've had is with mashing. I'd fondly imagined that I could just set the thermostat to 67C, say, and disappear for 90 minutes but what actually happens is that when the temperature drops and the heater kicks in, it over-compensates and the temperature goes up to the low 70s. It's still usable, you need to avoid setting the thermostat, keep an eye on the temperature and give it the odd blip of heat to keep it at the right sort of level. This is without any lagging, so as mentioned above that's something you could do to make it a bit less hands-on.