Just for kicks, I was going to try running a benchmark of this module on the nm5.in file in Challenge Problem: Merging Network Addresses, and since I'm on WinXP at the moment, I tried using ppm to install this module, and could not install it because it was not in ActiveState's ppd repository (yes, I know if it's pure perl I can just copy it, but I don't want to do that badly enough). When I checked the ppd build status, I saw that it failed on several platforms (Win, Solaris,HP). You may or may not want to address that issue in the next version, if possible. Even if I could run it on the nm5.in file in Dominus' test suite, I see that it would involve creating a rather large array using this method (then again, so did using Net::CIDR). I don't know how 'real world' that file is, so I couldn't say how fair it is to use it in judging your module. Just one issue to keep in mind when solving this sort of problem :-)
Update: Sorry, meant to reply to the root post. Also just noticed that this whole thread is a couple of years old, just saw it due to a recent post further down.