I'm a huge fan of Optimum's Power Clean. A month or so ago, I posed a question to whether or not OPC could be used in lieu of the more expensive P21s TAW. Not many responses but I opted to try it out anyways.
I originally tried the 3:1 dilution as recommended by optimum, and have had great results with it. 3:1 is stronger / more effective than P21s TAW, but it doesn't seem to have any adverse effects on the paint. The few spots that I have let dry have had the typical white haze, which easily comes off with a rinse of the panel or a swipe of the wash mitt.
On bugs and road grime, two applications of OPC have allowed me to rinse the front bumper cleanly without agitation via sponge. It also works really well in cleaning off exhaust soot from the rear bumper and exhaust tips themselves.
Overall for $35, I'm a fan. I've noticed no lubricity issues when washing with OPC + meguiar's GC.
Dave