I have installed the 5th Gen upgrade on all 4 corners of my 2003 4R Ltd (calipers and rotors), since both front calipers were seized (again/ 4th time in 150,000 miles). I chose to buy new Gen 5 dust guards for a clean fit. I also went with the "StopTech Sport; Slotted; Heavy Duty/Towing & Track" rotors as I tow a very heavy trailer often. Changed hoses all around while I was at it. Since this is a 'work truck', I didn't bother painting the calipers. I did not need to mess with the parking brake at all. Old rotors slipped right off, new slipped on. P-Brake still works fine.

I have driven about 750 miles in the last 3 weeks since the upgrade. At first I wasn't super impressed with the stopping power, but following the manufacturer recommended 'go easy' first 400-500 miles duration the Akebonos are now providing much better stopping performance than the stock system.

Smooth and silent. I'm happy with the results. Will likely do this on my '04 GX470 if they seize again.

Parts list:
Front Brake Caliper Upgrade Left CENTRIC 14144288
Front Brake Caliper Upgrade Right CENTRIC 14144287
Front Brake Dust Guard Upgrade Left 47782-60120
Front Brake Dust Guard Upgrade Right 47781-60120
Front Brake Rotors Upgrade Left CENTRIC 12644174SL
Front Brake Rotors Upgrade Right CENTRIC 12644174SR
Rear Brake Calipers Upgrade Left CENTRIC 14144588
Rear Brake Calipers Upgrade Right CENTRIC 14144587
Rear Brake Rotors Upgrade Left CENTRIC 12644175SL
Rear Brake Rotors Upgrade Right CENTRIC 12644175SR
Front Brake Hose Left CENTRIC 95044007 StopTech Stainless Steel
Front Brake Hose Right CENTRIC 95044007 StopTech Stainless Steel
Rear Brake Hoses to calipers Left ACDelco 18J4472 (Centrics kept shipping without the copper washers 3x)
Rear Brake Hoses to calipers Right ACDelco 18J4473
Rear Brake Hoses to frame Left CENTRIC 15044397
Rear Brake Hoses to frame Right CENTRIC 15044397
Front Brake Pads Upgrade AKEBONO ACT976
Rear Brake Pads Upgrade AKEBONO ASP606