Who else prefers 5751s and why?

I recently acquired a matched pair of 5751s to try because of all ofthe buzz about these tubes. They are the modest GE brand no black plates etc and I paid a fairly low amount for what truly appear to be NOS about $20 per tube. I immediately rolled the tubes in my tube integrated and was stunned by the improvement in sound, The tubes they replaced were real Telefunkens BTW, I have used Mullards and an assortment of other highly regarded tubes. None had the transparency, detail, both macro and microdynamics these have. The soundstage was also noticebley better even the speed of the amp seemed to improve. Has anyone else had this experience?
Ditto. BTW, that was a great price you got.
Yes, I have some Sylvania 5751's in my DAC and the improvement was definitely noticeable.

It has to do with gain matching. In the preamps I've used, the 5751 sounded horrible.
While you're at it, you can check out 5965 tubes.
I know this guy DEFINITELY thinks the 5751 is far superior to ANY 12AX7 variant http://www.audioasylum.com/audio/faq/joes-tubes.html

Maybe you fall into the same camp?
Gotta get the black plates - they are even better than the gray ones. Triple mica is also an improvement.
They have replaced all my 12AX7's with noticable improvement. Mine are the triple mica black plates.
I much preferred the 5751 in a Jolida JD100 CD player I once owned. In fact, I preferred the rather inexpensive JAN GE 5751 to some rather pricey NOS 12AX7's. However, I liked the 12AX7 variant better in a Jolida 302b integrated amp.
Yes the 5751's made a huge difference in my Jolida CDP.
There is good reason that you prefer the 5751s over a regular 12AX7. The 5751 was designed, primarily by RCA, as a low noise, lower gain tube than the 12AX7. It also has other characteristics that make it a little bit different than the 12AX7 (look at the curves).

One of the best versions is the Sylvania GOLD BRAND type. They are now become quite pricey as folks start to use them as substitutes for 12AX7s where gain is not too demanding and reduced noise floor is more important.
i have a ge 5751 black plate, which i use in an audionote cd player. it's my favorite tube, for reasons opposite to those stated above, namely it significantly rolls off the treble, adds a touch of veiling and takes the edge off most poorly recorded discs.

another great tube is a ge 5814 black plate. i have often substituted this tube for a 12ax7 in preamps or cd players.

you might also consider a 12ay7 as well.
I haven't owned the GE black plate. The Sylvania black plate has the least roll off. and is the clearest sounding of any miniature tube I have used.