I have been using fast track since 2005 and never had a problem.
1. Used on my layout from 2005 to 2015. Two main lines and several siding and 10 switches. (Layout taken down to convert space to a bedroom) layout size would have been 24 x 16 with two power leads per main line.
2. Floor layout for Christmas 2005 to present. Three large ovals using 072, 048 and 036 curves only one power lead per track. Another table top oval using 048 curves and one power lead. This is has been taken apart for 14 years.
For me I find it to be a very stable track system. I see reports several times of problems but I have never had them.
I do run an oval of Real Trax, now I have had several problems with it. However it is because of user errors. I just bend the heck out of those little tabs in the process of putting it together and taking it apart.