Actually it's not that difficult to update to the leak and rooting is a 2 minute, menu driven process. Don't bother with the old leaks, get the latest 213 leak. To install it grab the GB 219 STOCK blur and install it making sure it installs correctly. Then, before doing anything at all, install the latest (213) leak over the top of it. Then use the automated utility (top of this thread) to root, install Safestrap, Superser, OTA Rootkeeper etc.. Nothing special to rooting just plug it in and run the script. It reboots twice and you're rooted. Tested to work with all version of the leak.
Also there is now a CM9 ROM version for ICS you can install after rooting & safestrap. It's still considered beta but it does install and run. Just look at the first few threads under Droid 4 ROMS. I installed it yesterday and it works fine.