My WR already has a good low end, but I want more top end to keep pulling with my bud's CR250's. At the same time, I don't want to lose much of my low end. I've heard the Thunder Alley is mostly a low-end pipe. So, even though it gets raved about, I don't think it's what I'm looking for. So, what I'm considering is the FMF Powercore IV, the Dr. D and the White Bros. Pro-Meg. Does anyone have any comments about these three or other pipes they think will boost the top end. Thanks.