I have recently completed my capacitor upgrade, having bought the upgrade from Rob Gillum (rob@coherentsourceservice.com). It took 3 weeks for them to get to me in the UK. Most frightening 3 hours of my life doing the upgrade. I ended up removing the crossovers and doing all the work on the bench.
50 hours of listening in and I am completely and utterly delighted...sounds like a new system.
Definitely more detailed, speakers completely disappear in the soundstage and I am hearing better clarity through the whole frequency range. My wife says 'it sounds clearer' which is significant praise!
If you are still listening to your 2.4's, I really would spend the cash and upgrade them to the SE capacitors, I honestly think it's the best money I have ever spend on my system...