I heard some Sophia blue glass when I was doing the vintage work and a fellow sent me a quad to use with his citation II amp that I was restoring. Sounded good, but I only listened for an evening and the amp had all new caps and power supply so not really a good data point. I have not heard any other Linlai KT88, just the Kt88-D. I have heard their egg shaped 300b tube and it is quite good, but the WE300b copy is much better to my ear.