electro-harmonix vs svetlana tubes

I've seen the ads for electro-harmoicx 6L6 tubes allegedly better than RCA's (I strongly doubt that). I understand that they are Russian tubes. anyone have any experience with these as compared to the Svetlanas?
I was over to Brooks Berdan's place;(So CA) I'd not heard of the brand(making you second to mention them)-- Guess what tube he recommended for my RM9.2--- YUP E-H.

Ok,now this was for el34's-- I have a set of svets 34's-- Not my cup of tea;; Lacking in mid treble/ to the highest treble.Svets are flat up there;to me. Little more on the bottom,but not that much more. He never agrees with me/much; he did on this one.
The Electro Harmonix tubes are basically Sovtek.

The EH is the tube supplied in the Wolcott amps, and I have tried several tubes against the EH since buying the Wolcotts a couple of years ago. First, there is very little difference between the Sovtek and EH, the differences sited by Avguygeorge when compared to Svetlana is pretty much dead on. The other tubes to try are the Tesla E34 L, which is the best of this bunch, unless you can afford Mullards. Mullards are so much better than all of these that the discussion is ended when they are plugged in for the first audition.

Of course money is always a factor. The Tesla, EH and Sovtek are all similarly priced, the Mullards are expensive, even used.
I have a 300b push-pull amp and have tried both types.There is a very big difference in this type of tube and I'd assume this carries over to the other types of tubes .I feel and hear a more of the music whith the electro-harmonics,more depth more, I dont know .they just sound so good. I would like to mention another tube you may want to investigate they are called Full Music . I can't find there web address right now but if you do a search it should come up. Just my two cents like it or not
In my experience with EL-34's, the Svetlana's outperform both the Sovtek's and the Tesla's (I have not tried the E-H branded Sovtek's). In my c-j amp, the Svetlana's have the smoothest and most extended response at both ends of the spectrum, possess the more finely developed midrange, and give the best bass firmness. They also have the least "electronic"-sounding artifacts. I would rank the Tesla's number two sonically, but they have been less durable than either of the Russian brands.
I have both Svetlana EL34 and Electro-Harmonix EL34EH tubes that I use (not at the same time of course) with my C-J amp. The quality of both are very close and makes the choice one of personal listening preference. I usually like the Svetlana's just a fraction more than the EH because of the full mid-range. It seems that the EH tubes have slightly more gain and more punch in the higher frequencies. I cannot say regarding the longevity of either of these because I have yet to have either set long enough to need replacing. Both companies could work a little harder at reducing the distortion levels as compared to the NOS types.
The performance, and sonics, of both tubes, will depend on the circuit, they are used in. To me, the Svetlana's, sound better, when the circuit is biased, on the high side. The Electro Harmonix, does not seem to like this. As with all tubes, the end sonics, will be influenced by the circuit, bias, and amount of current, that passes through the tube. In one amp, they may be heaven, and hell, in another.