Class D is the future and continues to improve as solid-state did and tubes over time did. My next amp will be class D of some sort, no longer going to want to lift my 100 lb McIntosh amp which is superb. It will be sold at local pickup only at a reduced price. Just reality of age. Walter at Underwood going to be releasing a class D amp with the newest technology for $3,000. Cherry Class D, Merrill class D, and one or 2 others.