I'll jump on with a positive review of the Pentastar fan. Robbie and the folks at Motech recently helped me change from a dual conventional fan setup (SRT fans) to the PWM Pentastar fan. It is absolutely amazing. As others, including Robbie, have mentioned it bolts right in, looks completely factory, and works really well. I never had an overheating issue with my LS3, but driving around at low speed my temps would get up to about 210-215 (completely normal). With the Pentastar fan, I think I've only seen it over 200 once or twice. Normal driving it stays at 190-200. It is quiet when idling, but has the potential to move a ton of air. I also have a vented hood, which helps remove some of the high pressure from the engine compartment when driving at highway speed, but the fan has definitely made a difference. With the huge fan blade, it leaves the back side of the radiator unobstructed, so air passes through more easily at highway speed. If you have heat issues, reach out to Robbie. He'll get you squared away!