Pretty much like Terry says, run it 1,2,3,4 with O.D. and T.C. off it's not a bad little trans for the average Street/Track. If you street drive it and like punching the pedal the trans will punch you back.
The 5R55 stock I can't speak of as I have never had one.
The TCI Super Street Fighter built off the 5R55 I can.
I have had it in mine since late 2011.
And it has a lot of miles on it.
I'm guessing but probably like 20K or so on the TCI.
As I said above it has been drag raced many-many times since 2011.
I have never had even one thing bad happen to it.
But .............
If you have IMO 500 RWT and 500 WHP.
It will not take constantly slamming the throttle to the floor while it is in O/D.
And it's not going to take it even if you are in 4th gear and slam it to the floor.
It just does not hold up doing multiple gear downshifts.
It will not hold up to constant drag racing either.
Not with cars running 500 Plus DYNO Numbers.
But if one respects the tranny and drives with it accordingly it does OK.
It simply comes down to a complete understanding of the limitations of the 5R55 either stock or the TCI SSF built unit.
That also includes the Level 10 5R55.
http://www.mustangandfords.com/how-to/drivetrain/mmfp-0708-ford-performance-transmission-build/
.