The Amperex EF86s on the Tube man's site are made by RFT in East Germany, or rather those were the ones he *used* to have. They're not quite the equal of Bugle Boys by any means, but very good nonetheless. RFT is the company that made lots of tubes for Telefunken and Siemens-Rohre during the years when solid state was rapidly gaining ground and tube sales were tapering off. The tube plants knew the end was near, so they stopped investing money in maintaining their tooling and began to cut quality, which is why most of the later production from nearly all Western tube factories is so poor. Many did what Philips did with the Amperex-labeled RFT EF86s, they discontinued their less popular types altogether and began sourcing them from Commie countries and putting their own names on them.
The Winged C Russian EF86s I've had in the past ranged from quite good to quite pathetic. Ditto for the 10 pcs or so that I have in my stash at the moment. I let the two best sounding ones I've ever had go with an amp I'd built, and they were (dare I say?) fairly close to Mullard in tone and clarity. But, they were the exception, not the rule. The problem is that there are no external cues as to which are good or bad! It's the luck of the draw as far as I can tell. All have a Winged C logo, but other than that the markings on most are different. A few have the glaring, Cold War "CCCP" on them!
Electro Harmonix EF86s are surprisingly good sounding, as good as the best of the old perf-shield Russkies, and waaaaaaay better than the worse ones. But, the one that'll really knock your socks off is the Tung-Sol reissue EF-806 Gold. AAMOF, I'm thinking about cryo'ing a couple of them to see what happens. Some tubes respond better to cryo than others, and if these respond well, they'll definitely be every bit as good as Bugle Boy or Mullard, if not better (if that's possible!).
Don't worry about noise in pentode mode with the EF86. It's probably the lowest noise small signal pentode ever built. Mullard specifically designed it for use in phono stages, studio microphone preamps, and the first stage of guitar amps. Very low permissable limits for noise and microphonicity are on-paper design parameters of the type.