Thoughtful comments!
I’ll admit that I have not heard or even seen the Willsenton R 300 amplifier. The company has been around long enough to have established a track record of both sonic performance and reliability. From what I gather on both accounts they do well.
Willsenton appears to fill a void between ultra cheap Chinese amplifiers and say Line Magnetic level of products. Even then, Line Magnetic has different model ranges based upon price and presumably sound quality. Purely a gut feeling on my behalf but I think that based on owner feedback, Willsenton is a very solid choice.
I look forward to your listening impressions with considerable interest. Given your posted experience with other amplifiers. I believe that you are certainly able to separate the wheat from the chaff (Both sonically and judging build quality).
Charles