FUD. The changelogs are clear and public. Most of people's problems come when they try to install them on systems that have been otherwise hacked and patched for years and years. If you install them fresh (after a fresh install of the OS), you shouldn't have any problems. YMMV. 
I wish this were true, but I cant even get BB2 official to install on my mostly stock 4000 with just a BigRAM+ in it. BB1 is fine, but as soon as you power off and reboot after BB2 you get a GURU and endless boot loop.
One day I will get this 4000 up and running again past a clean 3.9 install and get these damn BoingBags working so I can start adding in my hardware, lol!!