My Suburban has had DOT 5 in it since 2003. No leaks, and no problems.
Before using the DOT 5, I replaced every part in the brake system with new parts (except for brass junctions/banjos). Before buying any part that had any rubber in/on it, I called the manufacturer to confirm that the rubber parts were DOT 5 compatible.
My only fear about the DOT 5, it that spillage/leakage would silicone-contaminate my garage, causing problems when painting this or other vehicles.
Most likely, I will use DOT 3 on the pickup I am restoring. It will have stainless steel lines, and it not be heavily driven, and it will be no problem bleeding the vehicle every year.
For those who are changing to DOT 5 and using old brake system parts, rubber parts that have been used with non DOT 5 might not respond nicely to DOT 5 (I think this fact has been posted above).
