I've used a few, I'd NEVER use TTI/CPPA again, total nightmare for any kind of maintenance on the car.
Maddogs were ok on a low deck but required some work.
Proparts were also ok on the low deck but required some work.

I'll never do any of this again. If I ever own another big block a-body it will have a Bondobob front suspension and custom headers, or the Hedman fenderwells or TTI 2 1/8 step headers with the Bondo front end.

TTI 2" did have great performance though, and Ive heard the Hedman fenderwells are even better for power.

My next build will probably be a stroker small block, much easier.

Had 2 in tti for my low deck with torson bars. I never had to remove the bars. I did not have stock engine mounts as I had a motor plate. manual steering. I would set the headers in the car with the starter laying on the drivers side header and drop the motor in, and bolt everything up. I got to where I could pull the motor in under 4 hours if needed. I even changed a few transmissions with the motor in the car. I now have an alterkation with tti step headers. I can unbolt the front steering linkage and drop the drivers side header right out. In any case I think having stock motor mounts in the car would make it way more difficult to install tti's.