We have swapped a stock motor LBZ from a cast 475 that he ran for over a year to a Bat 475 and he loved the improved spool-up and harder pull.
I have installed a Bat 475 on a stock LBZ with heavy 18" rims and 33x12.5 tires one week; then installed a billet 475 on LWatson's identically modified LBZ except stock rims with 265 tires and can tell you that while the truck with bigger/heavier tires should have felt slower it spooled a slight bit better and pulled a little harder in the top end.
I have personally run cast S475s and have tuned trucks with cast, billet, Bat, and Double Bat 475s. One of my employees has a double bat 475 on his stock motor LLY.
We have installed and tuned plenty of S366s - cast, billet, Bat, and Double Bat.
Like Mark I am a firm believer in the results of the Bat and Double Bat wheels. As a BullsEye dealer we can obviously still get the older style billet wheels if we want them, and could do like other shops and make more money by buying box unit BW turbos from BW distributors and then swap in BullsEye (or "our own design") billet wheels.
My personal daily driver will be getting a Double Bat S366 - the LMM that Jonathan mentioned sold me on having that turbo on my daily driver. Awesome spool up and is flat out impressive in the top end for a "little" 300 series charger; and staying in the 300 gives me some boundaries for the truck so that I'm not tempted to keep pushing it to the next level (that's what the race truck is for).
All of this is comparing BW based to BW based. As has been mentioned Precision turbos are in a whole different financial class and I haven't had the opportunity to run one.
Well put Dustin.:thumb: