I just got my car back and had both of these services performed today on my GS4 with 68k miles. All I can say is WOW, what a difference! Quicker acceleration, and less of a sluggish feel when hammering the gas.
I wasn't really sure if I neeeded to do this as I've always run premium gas and have used Techron every 4-5k, as well as the Amsoil Perfomance Improver gas additive 2oz to every tankful (other than the tankful when I use the Techron).
I'm not sure how "bad" the injectors were as the tech said there's no way to tell unless the car is exhibiting problems before hand, which mine wasn't. He also said the buildup in my throttle body was "average".

Cost me $145 for both of these services combined, I'd recommend it highly.

 

Cool, I have 93K on my GS300; I'm going to get theat done also. Did you get these services at the dealership or did you go elsewhere?

 

At an aftermarket shop. I'm very fortunate that one of the Lexus master techs in my area left the one Lexus dealership in my state and just opened his own shop.

I do know both the injector and throttle body clean are services most Lexus deaslerships offer, bu they'll probably nick you for a few more $$ than an independant shop. Even then, well worth it..........