Update:

I went ahead and reset the ECU. I am glad I did, to it for a ride.......I can feel the power.
THE PUNCH IS BACK!!

The set of venturis just arrived from Borla. I will have them in later today.
The sound is also settling.....less obnixios tha yesterday.

 

Conclusion:
I can definitely feel some power gains by having the cat back system installed.
The sound on the outside of the car is absolutely fantastic. The proper V-8 sound.
The unfortunate part for me is the sound inside. I can't stand the low rpm drone.
It's not too bad if you drive it in the manual mode, if you drive in AUTO it is awful.
The sound creates a slight vibration throughout the car at certain rpm. Even after installing the Venturis.
Maybe, I am getting too old for this or I am not as much "fast and furious "as I used to be :-)
I am going back to stock

 

If it vibrates they didn't align it correct when they did the Install. Also put the car in snow mode if you want the low take off drone to be reduced this believe it or not helps with getting better gas mpg as well.

Justin

 

How many miles have you put on the exhaust? It typically takes a couple hundred to break-in and will be quieter. I felt the same way when I first purchased a JoeZ exhaust for the car several years ago. I was ready to go back to stock immediately, but I took the advice of others and waited for the break-in and it was magically quieter.

 

Thank you for chiming in, I believe that the exhaust would possibly settle down a bit.
But, for me it was an eye opener, I absoulely love the luxury part of my car, being able
to peacefully drive if I choose to. The dual personality of the car is priceless to me.
Maybe I am getting older. I switched back to stock already, it was a heavenly drive home.

 

If you want to hear obnoxious you should hear my CLK long tubes no cats dual 3 in and just mufflers loud but at cruise and highway zero drone evosport did my full system before going for the charger.

 

correct me if i'm wrong here guys, but from what i've read from others the Borla catback alone will create some drone. When/if you install a set of headers the drone goes almost completely away. something to look forward to maybe i currently just have headers and cannot wait to get my hands on a borla!

 

I wanted to go Borla because I heard its the least drone/annoying for a DD. Are there any realistic gains in doing the exhaust vs the whole cat back system? Worth the extra $? I guess its not really about the $ but more so being able to make it sound better, perform a little better but be able to drive the car every day.

Also is it proven that driving in snow mode gets better MPG? Is this true on all Lexus/Toyota or just our ISF?