That's my experience in Custom, Sport and Sport S+. The IS 500 and RCF have the same transmission. I have limited seat time in an RCF and only 1100 miles in the IS 500 but they feel and perform the same. I just got rid of a 2021 IS 350 FS DHP, which has a different transmission, put 8K miles on the car, and the shifting dynamics did get more aggressive in Custom/Sport/Sport S+. The 500 and RCF seem to shift a little faster than the 350, but I wonder if it just feels that way because of the added power.

I'm quite certain the transmission in the 500/F is a bit quicker to shift. It is noticeable in my experience. Though, I will say the 8-speed in the 350 is a step up from the 6-speed in the AWD cars in terms of shifting quickness.

It seems like I really have to push the car to get it to really perform like I want, but I guess that's okay since I have paddles.

I've only had my IS500 for 2 days now but it's my third IS. The 8spd feels similar the 6spd auto I had in previous IS350s in some circumstances. I think it holds the car back a bit but I shouldn't complain since I think it was basically the world's first 8spd auto (debuted in the LS?)
Also coming from a ZF 8spd and once you have that, anything else seems a bit sluggish. That said, the ZF can shift a bit too smoothly, if that makes sense. It may sound weird, but I like the drama and theatre of shift shock as I feel it adds to the driver engagement.

I absolutely LOVE the DCT in my M2C. It functions just fine in auto mode and is a blast when shifting manually.

I agree. Dual clutch in my TTRS is just fine in auto or manual for daily driving.

"There's a reason bmw went back to a very good auto trans." Let's be clear, we're talking about the well regarded ZF8 - big difference. And BMW's reason is cost - with the ZF8 being close enough to DCT performance. With that said, I believe the V8 will make up for it as someone said above.

I had the 8ZF in my previous 340i and it was really good.

I can only imagine what it'd have been like to have a DCT in the IS 500 or RC F. I have only driven a handful of DCT cars - I owned a Mk7 GTI with the DSG and a Mk7 GLI DSG immediately after, and I have driven a Porsche Macan Turbo and a 981 Boxster S PDK. The PDK is on a whole other plane compared to the VW DSG, but even the DSG gave a nice mechanical feel that I don't get from torque-converter autos. The ZF in my wife's 330i is a really nice middle ground, where it's smooth off the line but is tuned to be more sporty-feeling than, say, the transmission in my IS 350. It shifts extremely fast, but it never quite feels as snappy as those DCTs did (even in the case of the GLI). The thing I liked about those DCTs was that they are both quick AND smooth to shift (outside of Sport mode in the GLI for some reason), so that the car isn't upset by the shift. I feel that the ZF has some engineered shift shock in my wife's 330i. And the downshifts will never be as good as they were in the DCT cars as well. Even my GLI had amazing downshifts - super smooth and quick to get the revs up. Maybe one day Lexus will come around.

^^ Its funny you mention that because some car companies have not had good luck with DCT (I am thinking of Hyundai which I know is not the pinnacle of auto industry) but I always pictured that DCT were sometime jerky, especially at low speed but I never had one so I am not an expert. I don't mind that Lexus is using the Aisin 8 speed in the 500, I mean for my use, I don't need these lightening quick shifts but I know we are all different. I mean all my Lexus products (3 IS and 1 RC) were all AWD because we can't have RWD in Canada (except for the 4 cylinder IS that no one buys here) and I never really had any issue with the 6 speed.

I was happy with the ZF8 in the m240i as well, and I would have been pleased if they put it in the IS 500. I'd even settle for the LC 10spd . I suppose you can't have it all.

DCT's are definitely not the smoothest in full auto mode, but they do what they can. They make a little bit of drivetrain chatter when connected to the M electrical LSD. Also, the weirdest thing I think about them, is that if you are on a hill, and take off the brake pedal, they will roll backwards just like a manual car.

Oh and they are a lot heavier (I think?) than a torque converter auto.

^^ Thanks for the insight, not ever owning one, your perspective was appreciated to thanks for sharing

DCTs are considerably lighter than a torque converter auto - it's more like you have two smaller manual transmissions put together.

And yeah there is definitely some "chatter" and weirdness at low speeds, but I found the DSGs in my VWs to be incredibly smooth and refined once I was up to speed.

Thanks for clearing that up. For some reason I thought they were heavier.

I think more research is needed into that, it's always been my impression that dual-clutches are amongst the heaviest transmission type on average, at the very least they are much more similar to a torque converter than a manual or single-clutch automated transmission in weight.

I currently drive a Golf R with DSG and it's basically seamless (although it suffers from very slightly rough shifts in manual mode if the fluid is totally cold, the only flaw I can find in 30k miles). I personally don't think DSGs are 'jerky' at low speeds, if you know how to drive a manual transmission (and therefore understand clutch engagement) you'll have no problem being 100% smooth in a dual-clutch.

Hey DCT's are fantastic all the time if you just drive in manual mode!