would you explain what is different exactly? is it sportier or handling better than the factory non-f-sport stock? most of the time my wife drives our IS350-C. I am thinking to replace mine if it improves car handling and stability.

 

Previously, the car kinda plowed in turns. Had to take turns kinda slow and you could feel the body roll. The new bars noticeably cut body roll and made it feel less top-heavy. It's like going from a small SUV to a sedan, that kind and magnitude of difference. Driving on sweeping highway curves is more engaging now... Too bad that's the only kind of slightly interesting terrain we have in Florida. Would love to take the car to a more mountainous area to stretch it's legs now!

Yes, sportier and better handling than the stock IS350c with no F-Sport mods.

 

Have since obtained Lexus Is F Sport sway bar kit PTR02-53082 installation instructions;

 

That's nice of you to post the install instructions. I did notice that the sway bar instructions are for the sedan version of the ISx50 as the IS Convertible rear sway bar install is significantly more laborious to complete (I've done the swap for both models and the ISC version was a huge pain due to the removal of multiple chassis braces and having to keep the rear subframe stable using a jack).

Here is a thread that I made to give others a heads up on what to expect with the swap:
https://www.clublexus.com/forums/is-...pressions.html