Best 845 tube out there?

I am running a pair of Cary CAD-211AE monoblocks with the standard no-name Chinese tubes shipped by Cary. Whilst I am happy with the sound, I think I should buy a pair of 845's to keep as backup in case something happens to these tubes.

Because I will need to buy FOUR of them, this rules out any tube that sells for stupid money (e.g. vintage RCA 845 tubes).

The only current production 845's I am aware of are:

- Shuguang 845 "standard"
- Shuguang 845B
- Shuguang 845C
- Shuguang PSVANE 845
- KR Audio 845

I have found reviews of the Shuguang 845B and 845C, but there is virtually no information out there on the new Shuguang "psvane" 845. Has anybody heard this valve, and is it a noticable improvement over the 845B and C? Also, what do people think of the KR?
Olivier, thanks for the report.  I have what sounds to be a similar system and I notice that "shouting" sensation on a lot of stuff that's new...hopefully you'll hear the voices move back in the soundstage with some burn-in, as you suggested...I suspect you will.  I am coincidentally demoing an Aqua Formula DAC, which by all marks should be phenomenal in all systems, and it sounded exactly as you describe at first--took a long time to burn-in/settle-in and balance out in my system, but it finally did.  Also, check your vibration/isolation of your amps...these tubes might be more sensitive to vibration than the others?  I've found Vibrapods and the like to help mellow-out shouty vocals in high sensitivity speakers, all else equal.  Let us know if the burn-in helps, please--hope it does for you!
I'm also interested to hear how Oliver's tubes mature. I am back listening to my Psvane WE845 but I know at some point I will need new ones hence my interest.
I will come back at the end of the week and tell you if some changes are observed. It should obviously, but will it change in the good direction? we'll see. 
Parsons, I indeed have Sorbothane pads under the amp. 
I would like to say that so far what I hear is not an evolution of the 845B, but rather a different family sound and signature. 
More to come...
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After 100 hours of burning I can confirm that I like the WE845 Shuguang better than the 845B, despite the non-consistent construction of WE845 (internal is not as solid and fine built as the 845B, one on my 2 tubes is even weird to look at inside).
So I made another direct comparison by exchanging the tubes and warming them up at least 30 min before listening. 
The WE845 definitely brings more flesh, more tri-dimension soundstage, and punch as well (although this is not what I was looking for). The main thing is the midrange much thicker and "material" than the 845B.
I wish Shuguang could be more serious about the construction of these tubes, whether they are imported directly from China or from TAD, the few guys I know from other forums had the same surprise to see the weird internal assembly of those tubes, sometimes even broken.