So basically only the systems that mimic the stock system are safe for street use is the feelings of many of the folks on here. I guess the question my curiosity really wants answered was what are the major differences with the xv level 2 stuff and the rms setup. Is the xv system worth the extra cas or are they both he same and not street worthy?
Obviously the stock set up has been proven for its durability. IMO, others are also very street worthy, but may not necessary be a "build em and forget em" them scenario. If you enjoy inspecting your car's systems as a part of the ownership experience, aftermarket set ups will live a long life. If you don't want to work on the car any more than necessary, a stock configuration may be better suited to your needs.
I believe there is a case to be made for diminishing returns on investment for most of the suspension systems on the market today. By that I mean you can get a set up that is capable of being better than 96% of the drivers out there for under $3k. To get to 98% will cost you an additional $3k. To get to the 99% range will be another $6k on top off of that. None of these prices include wheels and tires either.
The specific differences between XV and RMS are subtle differences in layout, materials, and base components. FWIW, John Buscema-who runs XV and has extensive road race and high speed experience, look at the RMS package before starting XV and decided to come up with his own set up. Some specifics - RMS uses steel tube, XV uses aluminum. RMS uses Mustang based components, XV uses Corvette based components. RMS has come up with spring/shock combos based on engineering formulas and empirical observation, XV has spring/shock combos derived from enginering formulas and four post testing. RMS uses brakes from Wilwood, XV uses Brembo. RMS has a sterling reputation for service and support, XV regularly blows deals by being out of stock. RMS components tend to arrive inspected and ready for install, XV parts have had some sub-standard components slip through.
-For you, safety and maintanence seem to be high concerns. In these points the stock style set up may be best.
-RMS and XV are significantly lighter than stock. If weight is a concern, these may be better set ups.
-RMS and XV allow rapid spring rate changes. If these are important, the may be the better set ups.
-All are capable of producing road holding capability up to and in excess of 1g.
-Stock style set up and be put together for a quarter to half the cost of RMS and XV. If budget is a concern, stock may be the best set up.
-RMS and XV look very impressive. If ooo and ahhh at the drive in is important, these may be the best set ups.
-RMS and XV have geometry corrections built in, if you push the envelope in driving, they may be the best set up.
If you base street worthiness on Eburgs opinion of heim joints, cantilevers, and distance spans, then no, neither are acceptable street systems, and in that case, neither is Hotchkis. For that matter, I don't think my Honda would qualify either. If you base street worthiness on the ability to never need inspections, then no, neither qualify and the stock set up is only marginally better. If you base street worthiness on number of miles accumulated, there is no contest that the stock set up is where its at. As I originally said, the best set up is the one that serves your peace of mind, meets you budget requirements, is capable of meeting your driving capabilities, produces predictable and linear performance, meets any rule requirements you may run into, makes you feel good about your car, impresses your friends, or any other of a hundred other intrinsic points that only you can know. Maybe you should list out all the pros and cons of the particulars your consider important with weight factors of each point and then you can see where they all fall. That tends to make decision much easier when laid out that way.