I run the Genalex Gold Lion PX-300b in my Beepre with Shuguang Treasure 300BZ in my Paramounts. Both are very good tubes. They are my favorites after trying several Chinese and European varieties. I get better bass with the Gold Lions in the BeePree, but my speakers don't have much below 50Hz. They both give me the mid range I would expect from a 300B. I think the Treasures may be a little more refined in timbre, but the Gold Lions are dynamic, detailed and provide palpable imaging and soundstaging. Both have been faultless in long term service. I could live with either one in the pre or the power amp.
Cheers,
Geary