My experience with the Willsenton R8 is totally different than what shtinkydog encountered. A friend of mine asked me to buy an R8 for him and have it delivered to my home. This was to prevent the bark, bite, and beatin' he might get from the wife.
I ordered it through Amazon for a no-hassle return and have been listening to it now going on two weeks. I am impressed with how quickly the order arrived, the packing materials, the build quality, and the sound. I have Wilson Audio Sabrina speakers in a medium size room. The Wilsons are 4 ohm on efficiency and 87 dB on the sensitivity, and I listen mostly to jazz. In triode operation it had no problems at all. I have had many amplifiers over the years and this one held its own quite well. The music power of each note caught my attention. I switched to ultra linear only for a few minutes. It sounded more forward and lit up but since triode sounded so good I switched back.
I will be delivering his R8 to him in a few days, and I have to say it gives me pause to even consider getting one of my own. This is a great value looking at it from my experience.