Unlytic v.s. Electrolytic...

Anyone knows an audio equipment where Unlitic caps used instead of electrolytic?
What are the advantages/disadvantages?
In unlytic cap's specifications they claiim to have 10x larger current density and 3x higher overvoltage protection than electrolytics. According to this comparison how should I select the replacement capacitance and DC voltage?
It's time for my amps to change the filter caps and I find troublesome to find an original replacement.
Under taking a number of measurements I can "afford" spacewise to accommodate only one unlytic cap which has 3" cylinder diameter. Originally I have 4 x 1000uf caps and 350 VDC.
Can you provide a link to information about what an Unlytic or Unlitic cap is?
Sorry for messin' with vowels it's UNLYTIC and the information can only be found here: http://www.electronicconcepts.ie/display_product_details.asp?29
It looks like the UNLYTICS are a metal film capacitor, definitely a step up from an electrolytic from a quality standpoint.

An electrolytic capacitor's main feature is that it can pack a lot of capacitance in a small package. The UNLYTICS don't seem to provide the same density.

Your current configuration consists of 4 - 1000 uf capacitors. These are wired in parallel to provide 4000 uf effective capacitance @ 350 working volts DC. Thus your replacement solution needs to come in this ballpark.

Since you can only fit one UNLYTIC capacitor in the space available, and the maximum capacitance per UNLYTIC is 1600 uf, it looks like they won't work in your application.