Help me decide which E88CC tubes i should buy

What would the advantage/benefit be of using EL83 or 8BQ5 instead of EL84?

Has anyone experience with the black plates RCA and GE grey ovale plate from 1960? And Sylvania black plates?

I am using Tungsram EL84 now, not sure if the RCA or GE would be an upgrade.

Seems the Tele E88CC's are ~~The Holy Grails~~~ as prices are $$$$$...I'm not so sure about E88CC's beating out ECC88's. 
I have my doubts.
I am rolling Siemens, Tele, Philips (= Amperex). and can hardly say which is superior in my cayin CD17 player, running a  pair on the unbalnaced out.
Maybe its not the ideal unit to makea  shootout.
I am very interested in these E288CC's I'm been buying lately. 
 
The list goes on, E188CC
PCC88
Ecc**
E88CC's, a  EU seller I've been buying from, maybe Bulgaria, says he perfers the E88CC's over all. 
again, I'm not so sure there is a  ~~significant~~ sonic dif in any of the above mentioned. 
I was surprised the E288"s ~~~failed~~ in shooting out all /every 6922 variety. 
Still , all in all, I'm hanging with the E288CC as it 's a  cool looking tube, and its a  ~~done deal~~..
Tele ECC88 just arri9ved today and again, did not hear any significant gain.
All sound ~~spectacular~~~.
I am not even going to attemp winning the Tele E88CC's on ebay,,although i am in the bid war,,I'm going to hold at $100,,and figure they'll fetch $160 winning bid. 
I am not going to chase the ~~Holy Grails~~ I think its all ~~snakeoil~~~.
I have a  pair of Tele's E288CC's, made by Siemens, NOS/NIB up on ebay, if anyone is interested,. also have Siemens 6DJ8/ECC88/pair/NOS/NIB +Philips Miniwatt PCC88/qaud/Test strong. + alot of other E200CC;s, amperex, Tele, Siemens, all NOS/most NIB. + I havea  pair of rare Dario Miniwatt E288's(but have to find them)), NOS.
As I say, all 6922's variations seem so close, its more inportant what caps in the unit.
I have new M SGO caps, which was a  huge gain. IOW a  new cap mod will mod the sonics far superior to any ~~Holy grail~~ Tele;'s. 
Just my 2 cents. 

I am not even going to attemp winning the Tele E88CC's on ebay,,although i am in the bid war,,I'm going to hold at $100,,and figure they'll fetch $160 winning bid.

I know a guy that has been selling tubes for 60 years he is on Ebay aswell, very trustworthy and honest, he has a pair of Telefunken E88CC for sale in NOS condition for 117$.

If you want i can send you the link.

E88CC's, a EU seller I've been buying from, maybe Bulgaria, says he perfers the E88CC's over all.

Can you link me his website?

I am rolling Siemens, Tele, Philips (= Amperex). and can hardly say which is superior in my cayin CD17 player, running a pair on the unbalnaced out.

Those are all mighty fine tubes, probably all equally good just different.

I have dutch Philips aswell and the they differ from the Siemens because the guitars in rock and metal are the loudest with the most emphasis. It's as if someone said during recording "hey bro lets crank those guitars up" can be fun for metal/rock and other music feautirng guitars but kinda dull for electronic.

Hi
Yes in my Cd player application , all 6922 variants sound very close,,even the big boys the 288's sound exactly like their smaller brothers.
which surprised me, i was expecting a  hugev  gain with the 288's. ,,,,they are about 1/2 inch taller, so should equate in longer life,,,i just like the looks of the taller tube and tahts the one i plan to keep, all others will be sold off.
Yes the Philips 12AX7 is a  great guitar tube, not so much much hifi, the Tele's beats all other contenders,,,very close to the Siemens.
Tele AX is the best AX.
AU's i hate, Next to the E80 the AU's are crapo.
Not sure why audiophiles are so stubborn and hang with the AU, when they could esaily go with a  Big Bang E80CC.
The E80 is a  drop in for any AU. 
IMHO the E80 will be the next and final Holy Grail. 
All E80's are equal, as all were made IDENTICAL construction. 
well should say very close construction,,I perfer copper posts. 
Tele E80's are Siemens, Tele never made the E80.
I havea  very nice stash of E80's some up on ebay..and will buy more , only at bargain prices,,as I say, they are NOT selling, as old school audiophiles just keep kicking the same AU can down the road.
You know how audiophiles are, Not me, I like to reserach and experiment.
The E80 has already been discovered as a  easy drop in for the AU, but still, its not popular. 
The E80 is the biggest gain in any AU socket, far superior mod in my sound vs the Tele AX's. 
The E80  magified the gain easily 2X' factor,,where as the TEle AX gave a  small nudge. over the Siemens AX. 
My 2 cents.
Mullard, Tele, Siemens, Philips, Tungstrun ,valvo, all built nearly and sound nearly identical..Thats said, I perfer the Valvo by a  thin hair. ,,,but that tube roll needs more time.
valvo Red, valvo white label, both the same as all other E80's. = E80= E80.
BTW, I am not a  believer in this snakeoil pinched waist, getter, dif color shields,  thats all bunk and pure 100% snakeoil. 
Yet folks love to pay $$$$ for ~~~pinched waist~~~ snakeoil