While I am not a former S4 owner I did cross shop the two before deciding to go with an IS-F (hopefully picking one up this week...). When you get a chance, can you let us know a little more about your S4 experience?
As for my reasons to go with the F. Appreciation for the overall package, running costs, and reliability.
The package - while the early cars are a little stiff, I love the balance of handling, braking, and acceleration in the stock F.
Running costs: insurance is comparable; the F brakes felt better stock (probably just perception or a difference in tires on the street) and are up for track duty with a pad change; You have ~ 80 hp more with the F out of the box;
Reliability - while the IS-F isn't inexpensive to maintain, after PMing people on forums for both cars and speaking to a few local enthusiasts, I was pretty confident that the F would be less expensive to maintain over the long run.
Here are a few pluses, imho, for the S4 though. Better fuel economy, AWD, and the ability to tune the engine if you aren't worried about a warranty. Yes, Stasis will give you a warranty with their tune, but that won't cover you with a CPO car or extended warranty - I plan to keep my F beyond 60k miles.
Finally, in terms of transmissions, they are both fantastic imho. The IS-F auto is one of the best transmissions I have had the pleasure of driving around on the street. Hands down the best true automatic I have driven, and on the street I think it would perform as well or better than most DCT's. I hope to provide a review of its on track performance in the coming weeks!
The DSG in the B8 Audi's is an amazing unit, and I really enjoyed driving the S4 with it. That said, I have read about a number being replaced, and the local Audi dealers and independent mechanics here said it would be difficult to rebuild (i.e. they would only put in a new or rebuilt unit). I think there have been only one or two IS-F's with transmission problems across all of the Lexus and F forums. That is a phenomenally low rate of complaints in the internet era, and is especially impressive when you consider that people drag the IS-F with N2O, track it, and even turbo the car without a proper tune.
For any S4 fans out there I have nothing but respect for the car. If I hadn't tested a 2010 Lexus IS-F I would be driving an S4 (or a tuned Evo MR but that is another discussion for another time).
As for my reasons to go with the F. Appreciation for the overall package, running costs, and reliability.
The package - while the early cars are a little stiff, I love the balance of handling, braking, and acceleration in the stock F.
Running costs: insurance is comparable; the F brakes felt better stock (probably just perception or a difference in tires on the street) and are up for track duty with a pad change; You have ~ 80 hp more with the F out of the box;
Reliability - while the IS-F isn't inexpensive to maintain, after PMing people on forums for both cars and speaking to a few local enthusiasts, I was pretty confident that the F would be less expensive to maintain over the long run.
Here are a few pluses, imho, for the S4 though. Better fuel economy, AWD, and the ability to tune the engine if you aren't worried about a warranty. Yes, Stasis will give you a warranty with their tune, but that won't cover you with a CPO car or extended warranty - I plan to keep my F beyond 60k miles.
Finally, in terms of transmissions, they are both fantastic imho. The IS-F auto is one of the best transmissions I have had the pleasure of driving around on the street. Hands down the best true automatic I have driven, and on the street I think it would perform as well or better than most DCT's. I hope to provide a review of its on track performance in the coming weeks!
The DSG in the B8 Audi's is an amazing unit, and I really enjoyed driving the S4 with it. That said, I have read about a number being replaced, and the local Audi dealers and independent mechanics here said it would be difficult to rebuild (i.e. they would only put in a new or rebuilt unit). I think there have been only one or two IS-F's with transmission problems across all of the Lexus and F forums. That is a phenomenally low rate of complaints in the internet era, and is especially impressive when you consider that people drag the IS-F with N2O, track it, and even turbo the car without a proper tune.
For any S4 fans out there I have nothing but respect for the car. If I hadn't tested a 2010 Lexus IS-F I would be driving an S4 (or a tuned Evo MR but that is another discussion for another time).