The ‘S Spec’ tweeter and the ATC SCM50ASL Pro 9 inch 3-way Powered Studio Monitors

Currently run ATC 40 active towers which are great.  Looking at the ATC 50 active with upgrade of the ‘S Spec’ tweeter.  Soliciting comments from those who may actually know about the 50s.  I’ve no interest in any monitors other than the 50s.  Thank you in advance for thoughtful insightful comments directed toward this product.