Different application from Gordon's, but I have recently replaced a pair of Ampohm Cu with a pair of Alexanders and the difference is very worthwhile in my application, coupling driver and power tubes in my Eric McC 2A3 amp.
Caps have now had around 300 hours and sounding positively delicious, cannot hear a downside in this application.
Ever't'ing much mo betta - I like very much these caps.
Granted they are 0.47 and the Ampohm were 0.33 which was what I had, but bass extension is improved and the entire tonal palette seems more "fleshed out", upright bass and piano benefit a lot, but instrument separation and definition seems improved and handclaps seem to have gained flesh on the hands while the top end is neither ignored nor accentuated.
Listening to Jazz at the Pawnshop and being able to listen to the interplay of the musicians and their individual contributions as they pass it to and fro with the background of the live venue. Being able to appreciate what a great job was done with the mike placements and fairly basic mix panel used for the recordings.
Nothing emphasised and everything discernable, distinct and in proper proportion, both tonally and dynamically.