Decware Mini Torii single ended tube amp OR Wyred 4 sound SX1000 mono blocks ( Class D )?

Best is to do an A/B test and see if for the music and listening levels and distance you sit from speakers you notice a difference?. I mean 600Watts vs hand full of SET watts !!. You can use this https://geoffthegreygeek.com/calculator-amp-speaker-spl/ to check how many watts do you really need for a 96 dB efficient speaker. But nothing compares to a proper A/B test if you can pull it off :).

I have switching amplifiers powering studio monitors and powerful push pull tube amplifiers powering moderately efficient three way dynamic main system speakers. Neither is preferred doing the others job. 

If you could possibly audition the Mini's I'd bet you'd keep them. At the very least you'd have increased your first hand sonic knowledge of the possibility of using tube amplification.

Listen to the quality or rightness of the mid range and not the overall quantity. Your speakers may want a bit more tube power for that.

Love my mini torii with my Klipsch Quartets, sweet sound. load but not real loud

I've never had a class D Amp but I have had all sorts of class A class AB ect and after going to SET  i'll never go back. if you have the speaker efficiency go for it.  you can always sell the decware as they are popular so you really don't have much to lose well other then falling in love with tubes.