My old thread is back from the dead!
Yes, the F-sport shocks I received were the correct ones and the P/Ns that were listed on the F-Sport Website were incorrect.
When my IS350 went from being stock to having the F-Sport Sway bar, I immediately noticed a significant improvement in the handling compared to stock (as other members can easily vouch as well).
I was hesitant to go to the next level by installing the F-Sport Spring and Bilstein Shock combo because I was afraid that the ride quality would suffer. Surprisingly, the ride quality had actually improved with the car once the shocks and springs were installed. My wife was going to be the biggest critic because she didn't want the IS350 to feel as stiff as my Supra had but after the install, she said the car felt better than stock! With the exception of being careful with hitting small bumps on the road, when you are on a flat surface, the IS is highly responsive to any turn you can throw as the car feels completed planted. The significance of the improvement in handling with the F-sport shocks and springs was just as dramatic as the improvement in handling when the car went from Stock to having the F-sport sway bar. It was another Night and Day difference. Whenever I take the IS to the lexus dealership, the techs can't believe how smooth and responsive the vehicle feels compared to the hundreds of stock IS250/350s they have to service annually.
When there was the big Lexus event in NJ a few months ago to showcase the new LF-A, the Lexus IS-F and IS350 F-sport were available for drivers to test drive around a course. Many drivers that drove the IS350 F-Sport and IS-F around that track said the IS350 F-sport felt more responsive and predictable around the turns than the heavier IS-F. I cannot say enough good things about the set-up I have with the IS. It's essentially become a junior IS-F without the upgraded motor, tranny, and brakes but the IS350 is no slouch with its brakes, gearing, and stock motor. My personal opinion is that it's worth every penny and a great upgrade to keep me happy with the IS for another couple of years.