1. The corporate Email app is way better than AOSP Email
2. Better camera
3. Dialer. The mute and speakerphone toggles were really helpful!
In short, it sounds like I need a TouchWiz based ROM :-/
I have reluctance because the security enhancements in 4.4.4 also seem pretty important. I know Samsung hasn't released a 4.4.4 OTA yet, but are there any ports or 4.4.2 that at least have the openSSL and other security patches from 4.4.4 included?