Improving on Simaudio Moon W-5

I'm interested in improving on my Simaudio Moon W-5 of 10 yrs, and would appreciate a sense of direction from those that have experience with the Simaudio sound for comparison. Our audio system has grown all around this W-5/P-5 combo, and perhaps its time to consider improving the power plant to get the most out of the rest of the components. I really love the clarity, depth, punch, and articulation of the W-5, but have not heard more recent Simaudio designs to know just how much sonic improvement they offer. Open to any SS or hybrid designs w/ a budget cap around 6k, preowned. Thanks everyone ~