A better question would be, "what's different?". From appearance it has the same diameter, cone, basket, surround, voice coil diameter and power rating. Do you have any side and back photos you could post? I was considering purchasing the 327 component set, in addition to the D2 I already own, but if I've already got 4 of the 5" woofers it wouldn't make much sense. What are the woofer specs of the 327 component series (Fs, Xmax, DC res, imp, vas, etc.)? Virtually no specs are posted on your site so it's hard to determine their effectiveness in my application. Are they best suited for infinite baffle, sealed or vented? Since your drivers are advertised as audiophile grade you'd sell a lot more if you provided every spec you could get your hands on.