JimBow:
Your last post touched on what I was going to mention. There have been some recent articles that have talked about changing the stock grip on the Matthews. I have a XL-size hand (glove size) and find that the Matthews grip to be too large and uncomfortable. I believe Matthews makes smaller after-market grips that may help. Having said all that, if you are shooting a 3-arrow group as tight as you say you are, then the grip may not be of major concern. I would try reducing the poundage on your bow to around 65#. This will lower it some, but you will still be able to shoot the same size arrow. I don't remember you mentioning the weight of your broadheads. You might try going with a 100 gr. or even 85 gr.! Paper tuning will tell you a lot about arrow travel as it leaves your bow and I would first paper tune your bow properly with field tips and then try your broadheads. This will show you any differences in the two setups.
Sorry for the long-winded reply.