THe SV1 forks have complete adjustment. Some guys have just put heavier springs in and changed the oil.
Others have put the GIXXER front on. The GIXXER front is obviously a better front end. The only problem is if you get the triple clamps, clip-ons, brakes, and rotors. If you get that, and it is cheap, I would do it
Depends what kind of riding you want to do. For street riding and light track riding, the stock SV1K front end is fine. If you really wanna ride hard, I guess street as well as track, the front end should be upgraded.
I also replaced the springs with Race-Tech and put 5wt. Silkolene (rated #1) oil in the forks.
If you use thicker it will hydro lock the stock valving. If you do the GSXR swap, keep in mind it does lower the front end which then sets your weight bias even more over the front tire. This is good and bad! Bad for comfort but good for handling!
I am VERY happy with my suspension now. Gixxer rear shock and all...
pretty sure sv1k forks are same as the previous gen gsxr600 forks. so they are quality, cartrige forks.. but should be revalved & resprung to work their best. after they are reworked they should be pretty darn good. gsxr750 usd forks would be better only because they are stronger/more rigid... and because they look neato
Haven't gotten around to "advertising" the service yet, but your friendly local site sponsors at SVRaceShop.com offer rebuild/revalve/respring services for SV1K forks. We can even install race-tech gold valves in them if you'd like, as well as annodizing the fork lower tubes in cool colors. Available in the Online Store at http://www.SVRaceShop.com