I'm running it on our 2012 Lexi 283ts. It was designed to do more to improve the tranny shifting than to provide more horsepower.
It does increase hp maybe 10-15, but the real improvement comes from improving the shift points.
When going up a grade as on an x-way, no more dropping from OD into the "screaming third". Now it maintains OD, and then will drop into forth, and then into third, if needed. I run my cruise control alot, and find the tranny maintains its set gear selection a lot longer going up a grade.
Also, when cresting that grade, tranny used to stay in the lower gear for several hunderd yards. Now, it shifts back to the higher gear much much quicker.
Acceleration is improved a bit. You will notice it when under hard acceleration like entering an x-way on ramp, or passing. Not gobs of HP, but noticable.
If your expecting big increases in HP and performance, you might be dissapointed, but you will definately notice the improved "driveability" of the rig.
Happy customer, and whould buy it again.