What's more important, watts or capacitance?

I'm confused about what makes an amp able to reproduce musical transients realistically. Some articles I've read state that one needs lots of power, measured in watts, to handle dynamics, especially when pushing moderately sensitive speakers. Other articles refer to capacitance as the key. Currently, I use an amp with 600W / 900W into 8/4 ohms, and if I read the specs correctly, it has 60,000 microfarrads of capacitance. An alternative I'm considering puts out 'only' about 220W / 400W but claims capacitance of 200,000 microfarrads. So which amp will sound more dynamic? FWIW, my speakers have a sensitivity of 87.5 db, avg. impedence of 4 ohms and a minimum impedence of 3 ohms. I don't listen at real high volumes, but I do like classical music at close to live levels.

Thanks for any insight!