Elrog 300B vs Takatsuki 300B tubes


Has anyone heard the Elrog 300B tubes ? I read an article which mentioned that the Elrog 300B delivers 15% less power than a traditional 300B tubes. Can anyone confirm that it is audible ?

I am choosing between Elrog and Takatsuki 300B tubes. I would prefer the Elrog because it is cheaper and supposedly wonderful but if it really sounds less powerful then I have to rethink.
pani
Hi Charles (and other Frankenstein owner),

May it be that the filaments of the Elrogs are very bright after switching on the amp for 2 or 3 seconds and then the brightnes is decreasing within the next about 5 to 10 seconds?


Mk,
I haven't noticed that with my amplifier thus far. 
I thought I have another bad Elrog replacement tube a few days ago, no sound from one mono block. I removed it and use my EML,still no sound, uh oh. I had it check out by a friend who is an excellent tech. Turns out the recently installed cathode resistor had a bad solder joint. This was corrected and the Elrogs are working fine and sounding fabulous. 
Charles, 
May it be that the filaments of the Elrogs are very bright after switching on the amp for 2 or 3 seconds and then the brightnes is decreasing within the next about 5 to 10 seconds?

Brightness on turnon that slowly dies down is a sign of overvoltage on turnon and will quickly harm the filament.  This behavior happens in a number of 300B amps and the thoriated filaments light up much quicker making the behavior much easier to notice.

dave