Matrix
This is from the manual that came with my 2005 Matrix:
"Improved Hoyt Dovetail System Instructions:
Your 2005 Hoyt recurve riser is equipped with an improved version of the Hardlock dovetail system. The redesigned dowel allows you to make weight and/or tiller changes over a larger range without the need for a radial adjustment of the dowel. In addiditon, the stronger dowel material allows use of a 3/16 Allen wrench (supplied), which makes locking the system faster and easier."
The big change is in the dowel itself, the newer dowel holds the detente button securely without touching the aluminum of the riser. The older dowel had a slot all the way through which could allow the detente button to come in contact with the riser itself and eventually mar the aluminum. I don't know if performance could be affected by the older dowel, but any potential contact with the aluminum is easily avoidable by swapping out to the newer dowel. The newer dowel is rock-solid, simple to align, and IMO impossible to slip out of alignment. Its a shooter. You didn't ask, but yes, I Luuuuuuuuv my Matrix.