LinLai WE 300B or the LinLai Global Elite Permaloy 300B tubes ?

@sns, 
I believe that if you were to take a chance on the Elrog you'd really like them, beautiful sound. No audio product receives 100% agreement when it comes to listening impressions and preferences.  @brownsfan finds Elrog superior to the EML XLS , I do not. Different ? Yes but not better as each has its respective strengths.  We  both are  seasoned listeners with discriminating taste (Fair to say I believe). In other words we know what we like,  simple as that.  Bottom line, you can not go wrong with either genuinely fine 300b tube.
Charles 

Reliability and durability are an important consideration in my tube purchases. At this point EML front runner, Liquidsound's review of LinLai will have major bearing on ultimate choice. As he previously mentioned, and I experienced with LInLai 101 tube, build quality appears to be superior to Psvane, does this result in greater reliability, durability than Psvane? And then sound qualities matter a great deal.

MkII standard upgrade includes Nichicon Muse cap replacement of stock Rubycons in mine, volume transformer upgrades and rotary selector, yes volume selector upgrade. Above and beyond, I custom ordered Amtrans volume selectors, far superior to the standard upgrade volume selector. I know because I was going to diy the volume selectors, standard volume control upgrade still pretty cheapo Chinese part, Amtrans is jeweler standard build quality, unmatched precision (Chinese $6 each, Amtrans $108 each). Result of upgrades is bit more natural timbre (NIchicon vs Rubycon) and sound stage precision the MkI can't quite reach, solidity and depth of center stage so much improved, result more dimensional imaging.

@sns,
Thank you for the additional insight regarding the MK II upgrades compared to my original version. More natural sounding? That’s quite something as what I admire most about this Coincident Statement line stage is its pure and natural character (So pleasingly life like). Well anything (Certainly audio components) can be improved I guess😊.
Charles

+1 on Telefunken ECC83. Sounds better than Gold Lion in my amp - more detail. For power tubes, I was using Valve Art 300B's and then found Shuguang Black Treasure at parts connexion for half price. They both sound good, with the BT sounding more refined and better bass. At DIY audio, where I purchased my Elekit TU8600, they speak highly of the LinLai Cossor WE300B. BTW I love the TU8600 - best sounding amp I've ever owned.

@sns ,  Thanks for the details on your experience in upgrading the CSL preamp to MK II.  I've been considering this upgrade since it was first announced, and contacted Israel who didn't give much detail on what sort of improvements one might expect.  Did you buy the Amtrans and send it to Israel, or did he order it for you and do the installation.  I love my CSL and consider it my destination preamp, so I'd happily part with it for a while to upgrade it.