I currently shoot an MQ1 that is over 10 years old. I've yet to find anything that's a significant upgradefor me personally. I take extremely good care of my equipmentso thisone will probably be around for a while.
I shot a PSE Mach 6 for years before that which I still own. The upgrade from the PSE to the Mathews was noticeable, but I can still shoot the old hardcam just as well as the Mathews and it's fun to occasionally go to the 3D's and clean house with an 'antique' bow.