Thank you for using just answer.
I am very very familair with your car, aside from owning one I hae worked on these for too many years.......I can fully understand not wanting to spend $2,300 on a repair for a car that is only worth twice that.......let me ask you this- realistically how much longer do you plan on keeping this car? I have a few options for you to consider depending on yoru situatuion
Ok, let me ask you this then....if you drive the car over a speed bump does the car bounce several times or does it only shock/rebound one time?
Do you notice any noises from the front like a crunching noise...some customers describe it as a noise similar to pop-corn popping
ok, a banging noise is not mormal on this model.
We have seen a few issues with slight clunking noises and creek/pop noises as the sway bar bushings dry out or the upper strut mount bushings collapse but not a banging noise.
The electronic modulated air suspension was a very very rare option on the ES300, only about 5% of production had this option so you will likely never see another one yourself with this feature. In higher mileage these do tend to stick internally and the price for parts is extremely high. The Lexus LS400 had a electronic system as well and we commonly saw repair bills of $5,000 on these if they fail, not fun to explain to a customer.
My advise and recommendation on your car would be quite simple here to keep cost down. The electronic verses NON-electric suspension systems on the Es300 are physically the same size and the suspension components are interchangable.
If you are going to replace the struts here what I would recommend is to install standard struts/springs and mounts to the car. The electronic parts can simply be discarded and the switch disabled to keep the indicator lights from going off. This is the most simple and cost effective solution. If you do decide to invest the thousands on the electronic parts do be aware that they typically have a very stiff ride quality regardless of setting so you will likely not be happy with the car if you go that route.