out of interest, how much power do you think is being fed to the wheels under braking?
That "review" was anything but credible, but hey, there is nothing like a famous developer's name and some internet hype to get some viral marketing, right?
A transfer case rebuild will cost $1-2k depending on how bad the existing case is, plus remove and replace and fluids. Yes it can make an excellent different, particulary if the old one is in poor shape. It however also offers no adjustability like the controllers do.
I think a controller for a couple of hundred bucks is the way to go for most street users, unless you have too much money to spend. Once you talk about maximum performance for track etc it is a different story - I would (and did) do both a rebuild and a controller.
You can get controllers on ebay from $90 so it is a cheap bet: http://www.ebay.com.au/itm/GTR-Torque-Split-Controller-TSC-GTS4-GTS-4-RB26-Stagea-/110896719839?pt=AU_Car_Parts_Accessories&hash=item19d1f5a7df