Be careful dannybad, a lot of people around here are eager to advise on things they have no actual experience with. Differences between caps are easy to hear. I'm talking electrically same value caps. Back when I didn't know this the designer of my speakers sold me a tweeter upgrade that called for a different crossover. He gave me the circuit which when built sounded nothing like what I had heard in his lab. It sounded like crap! After asking a bunch of questions and being assured I used all the correct value caps and resistors and point to point soldering he finally asked which caps? Well, Radio Shack. A week later with a Hovland MusicCap and Holco resistor and wow, magic! Bye-bye grain and etch, hello lovely liquid music!
Bear in mind this was going from Radio Shack caps sold five to a pack for a buck fifty, to Hovland MusiCap sold one for about $35. How much difference you hear will depend on what you're comparing. In any case, as long as your values are as close as you're saying then virtually all of what you hear will be due to the caps themselves and their quality and NOT have anything to do with the values being slightly different.
If your crossovers are working then I'm not even sure why you would want to replace the caps, as there's a lot easier/better places to put your money. That said, if the caps in there now are as cheap as they probably are then you should be able to easily hear improvement in smoothness and detail when upgrading to some quality caps.