I've been running the leak since last night. Mine didn't overclock to 1.2 Ghz, still just 1Ghz but it's very snappy and fast with ICS. No lag swiping between screens, etc..
I noticed the ROM took a long time to "settle in". As I used it for several hours last night it got smoother and more responsive. I noticed especially that the first time I would open an app it would take forever, sometimes even hang or have other weird issues. Usually the second or third time I opened the app no such problems.
I love the new ICS launcher and menu, I don't feel the need to overlay a different launcher or a custom ROM at this point. I haven't tried it on my lapdock yet but I'm hoping I don't get the FC issue because I really don't want to install another launcher.
My biggest complaint would be that some of the apps don't really seem like they're optimized for ICS displays yet, either things look too big or too small. For example the weatherbug temp reading in my notifications area is so tiny you almost can't read it.
The only other complaint I've got so far is the scroll speed seems a bit off, it's "stickier" than on GB and I haven't been able to find the menu to adjust it. Beyond that I'm liking it so far.