There is nothing wrong with Muzzy's, nay is there anything wrong with expandables. If you double lung a deer with either, your results will be similar. However, you do need to address how your bow is shooting the Muzzy's. If you have a good supply of them, and they have given you good results in the past (as they have countless thousands of hunters), then I would stick with what you have.

If you prefer an expandable, your Allegence will provide plenty of Kenetic Energy to get the job done ethically, assuming you are hunting medium sized game, no larger than mule deer. Anything larger or more heavily boned, and I would stick with a cut on contact, supersharp broadhead.