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?