The 150's weigh 10 grains per inch while the 250's weigh 11, that will give you around 29 more grains, but more importantly is you could very well be underspined with the extra 100 grain inserts upfront and the poundage you are shooting, the extra weight up front is definatly a good thing in my opinion giving you a better position of FOC, or (forward of center) with your set up, I think you will be pleased with the 250's, and more importantly is of coarse the better tuning you get the straighter the arrow will enter your target thus much better penetration.