I’ve had Merlins, both floor standers and the TSM MMM Black Magic editions. They respond nicely to higher power delivery though Bobby P ran them a lot with ARS-Sonum tube amps.
I’d be careful with class D amps as anything on the lean side or bright on the top end will sound particularly bad with these revealing speakers. If you can find a used H2O S250 Signature, then you’d be in for a real treat. The H2O is a fantastic amp, detailed yet full-bodied. I haven’t heard Ralph’s amps but they’re on my bucket list.