I wouldn't expect any audible change. I am not going to get into the audible differences between different capacitors. There are tons of stuff and web pages on the internet about the subject. From my point of view any audible differences from switching capacitor brands would be minor and something you can experiment with and see for yourself. The cheapest bang for your buck and one of the best options would be to Charge Couple them using Solens like JBL does in the K2 9800,9900 and Everest. Compared to the cost of the botique caps it's a very inexpensive option.
Rob