I have had Ics on my DROID 4 since Monday and overall I've been pleased with it. There's a lot of good things that changed and a couple I don't like.
You can now take screen shots with your phone! Press and hold power button+ volume down key.
Lock screen I really like especially with the shortcuts to SMS and phone and theres also the option for the face unlock.
Silky smooth transitions compared to the lag I was getting on gingerbread to the home screen.
The option to go from vibrate to silent via volume rocker is back!
The music sound quality has improved: sounds fuller and louder.
Long click brings your running apps and just a dandy swipe kills them.
On the other hand...
Not a fan of the SMS looks... I preferred the way "bubble" look better
I've experienced a reduction in battery life... I'm hoping it's just because of the new software and it'll increase within the week
Overall well done Motorola!