I also have been on the fence about this....The alterkation is probably O.K and believe me I wanted one until a friend pointed me towards Hotchkis...The big difference...Cost Hotchkis complete front and rear is like 2500.00 plus a good box from firm feel...another 500 or so.
The RMS...4500 for the front and another 2500 or so for the back, I took a ride in the Hotchkis 70 Challenger a Carlisle and COULD NOT BELIEVE how good that car handled...The 70 Challenger ran a better time through that course that a new SRT8 Challenger and a new SS Camaro...Bottom line, Save some money and go with Hotchkis...