I agree on the XT6 even though I really liked my Turbo XT. The frame rail rust is a pretty big problem with all of these cars. My southern car even had signs of significant problems and that was 6 years ago.
But then I initially bought my GL10 XT Turbo for only $500 in 1994 with just over 70K miles on it. It had a bad turbo and would have been an effective military vehicle for laying down a huge smoke screen.
I was very lucky and found a replacement turbo for only $100. Then proceeded to put 90K more miles on the car and it was still running fine when I parted with it.
Lee