Just for ballpark u-value reference, you can expect the 5300 to come .02 worse (numerically higher) on the double hungs, and another .01 worse on the sliders. 5100 series is then .01-.02 worse than the 5300 depending on options, size, etc. Casements will be very close to the quoted picture window #'s.... In dh, the Acmaster will qualify for energy star @ .29-.30 in the 5300, whereas the 5100 needs Ecomaster to get the .30 or better. Those are for the northern region requirements.
Thanks that's very helpful!