There are two major differences...the amount of drop and cost. Spring rates between the two are relatively close. For the money the SVT kit (on sale at northcoast for about 260.00) is a screaming deal and will result in significant handling improvements (remember you also get the bigger SVT rear sway bar). I have the pro system and if the SVT kit was available at the time (2004) I would have gotten it. That's not saying I don't like the pro system either, its been great. But if cost is a major consideration the SVT kit is hard to ignore.