Yeah, if anything, I've found out that the vertical Kato rail joiner connections on Ttrak are the weak link, there's more vertical play and stress there than anyplace else. You can end up with a really rough joint, or a lifted end, or all kinds of mischief.
I've taken to drilling a hole and putting a tiny wood screw on my Kato ends as it seems like any nail I use pulls out, and any glue eventually gives. But that just forces the problem to the rail joiner rather than springing the track.
But even with that, stuff happens. Last year at Altoona I had Atlas GP's snagging pilots on track joints and a Kato GE-P42 snagging the pilot and derailing.
I carry a short straightedge, and some thin shims, as just clicking them together ain't good enough.