After playing around a fair bit my view is don’t assume you know better than the original designer and just replace any tired ones like-for-like with the best quality of the same type you can find, e.g. replace PIO with PIO, electrolytic with electrolytic and film with film. Anyone who tells you they all sound the same is deaf as a post and should be ignored! As documented on my JR149 thread I have two identical sets of crossover boards so can swap in/out very easily (plug-connector) and I spent some time comparing modern film caps to electrolytics (the original spec). It changed the voicing to a substantial extent, and certainly not for the better. I’ve heard exactly the same in electronics. This is not that film caps are worse, they are clearly better in pretty much every measurable way, it is that the speaker was designed and voiced using electrolytics.
Really good kit, i.e. the stuff you buy because you like the way it sounds against other options, has obviously been voiced by the manufacturer using the components that are in it. Change them at your peril, e.g. changing tantalum caps in a Naim preamp unquestionably changes the voicing, they are a big part of the sound you bought, same with changing PIOs to modern film caps in a vintage Quad, Leak, vintage Fender guitar amp or whatever. Once you do that you are way, way out on your own, it is no longer the product you bought, it is now a different thing.
Sure, some folk love tweaking and changing stuff, but to my mind it is too much of a crap shoot, far better to buy something you really love and just maintain it properly so it retains the sound you paid good money for. I’m also now very firmly of the mindset that if you do want to alter something ‘to taste’ you absolutely need two of it; one to keep entirely stock as a reference point, the other to modify. It is just way too easy to persuade yourself something is an improvement whereas on long-term re-evaluation against the reference unit it proves otherwise.