I have used ACT! for years on my PC. I switched to a Mac over 3 years ago. I still use ACT! on a Windows partition, but it is frustratingly slow to load and run in that environment. I refuse to upgrade my PC copy of the software. Instead, I am looking for a native Mac program with an integrated iPhone app to manage my contacts.
I didn't search the forum, but I'm sure I'm not the first -- or last -- person to make this request. You could really broaden your sales base and have market supremacy with Mac and iPhone versions of ACT!. If that reason isn't compelling enough, perhaps you'd create a Mac version just for me, your Suwanee neighbor and longtime customer!