I'm totally against being required to buy and install active avionics for someone else's use.
Passive collision avoidance and XM weather are fine. You can buy and install it in your own plane, upgrade it or replace it as improvements come along, and your wallet can handle it.
ADS-B is great for government officials and avionics manufacturers. For us, not so much. It's high tech now, but will be passed up soon with something better. Hopefully passive.
GA is getting so expensive now, that the FAA considers thousands of dollars to be an insignificant expense when they spend your money by mandate.
We should always work together to keep aviation affordable and regulation minimal.
80% of the people that start flying give up because of the cost. We lament the loss of pilots, yet some encourage expensive mandates..I don't get it.
XM is my choice.