I put the SW Cat Back system on my 2011 Coupe, last Winter. It is still stored on the lift, in my garage. The road salt is not yet washed away well enough for me to get it out for the Summer.
The first day I installed it, and the second I readjusted it. Be aware that I tend to be more than a bit fussy about such things. The system ended up quite parallel to the drive shaft, but located about 1/8" toward the passenger side. The exhaust pipes are nicely tucked up into place. I do share the concern about support since the mufflers are held up by a pair of rubber hangers, where the OEM system used three pair. The SW system does weight less. I have not yet the weight difference, but plan to do so.
After the attached picture was taken, I fabricated a center "hanger" to use in place of the OEM one. Actually I just cut and drilled blocks to space the standard bracket further away from the body. That with longer bolts, about 4", did the job.
Overall, it is a nice installation. I look forward to soon experiencing the sound. Backed into the garage it does sound nasty.
Before someone asks, I haven't pulled it out because the wheels are still off. That not only protects the tires, but allow me to lift the coupe higher up so my Tundra fits under it.