It's a pretty complicated issue, I guess. Since King Arthur Flour is pretty much all I buy, I checked their blogs to learn more about a cake flour vs. regular. You can read all about it here:
http://www.kingarthurflour.com/blog/...of-cake-flour/ They discuss all the pros and cons for pound cake, etc. Good luck. I don't think I've bought cake flour in years, but what probably matters is the recipe you use. I think you can get good pound cake recipes on King Arthur's site and see what you prefer. Happy baking!