Interseptor,
For what it's worth, I'll throw in my $0.02. I shoot a 54# @28" BW longbow. I draw 28", maybe just a tad over. I have always used 29" 65# cedar or birch with 160gr point and decided to try CX this year. I ordered the test kit from 3Rivers and settled on the CX250s cut to 30", 100gr. brass insert, 160 points. I ended up around 640 grains after fletching, etc...I still shoot the bare shafts once in awhile just to check things out in between fletched arrows and started noticing that the were showing a little stiff, not sure if I didn't notice it before or not, but I then tried the CX150's, cut to 29", using the same 100gr inserts and 160gr points and they fly so well I'm going to switch. I'm still over 600 grains on the arrow so I'm happy with that. Hope this is of some use to you.
Ken