uberwaltz - Several have told me that those speakers do amazing with cap upgrades. Even with relatively inexpensive caps like Mundorf MKP or Clarity CSA.
I think it's a very inflated story. I just recapped my ~35 years Heco speakers to a disappointingly minute difference. I mean, 9 out of 10 people will not notice the difference. Only a very very slight change in transparency and twitter level and I think the highs sound harsher now.
The original caps were bypolar smooth type and I recapped with Jantzen Cross-caps (MKP).
I'm not saying it doesn't work, but the speakers need to be very revealing and the caps probably need to be of higher (more expensive) class. It's not night and day on old equipment.