This discussion has gone onto a tangent, oh well.
Your experiences seem similar to those over at mu-43. When I first started using it, I "thought" I needed to underexpose more than I normally would, like I do on the E-P1 to protect highlights. What I figured out was that the E-PL2 screen brightness is higher by default. I also think the dynamic range of the screen is also lower, even though the overall brightness is actually higher of the PL2 screen, in comparsion to the E-P1. Other's have commented on this over at mu-43. I think what would be nice is for a contrast adjustment on the screen as well. I also don't care for that real strong blue tinge the E-PL2 screen has, either. I think it is an AR coating type thing, and works good in sunlight, but in normal indoor light, it really isn't that nice.