I've been using the same vintage tube electronics for many year- pre-amp with outboard power supply, and two mono amps which employ 4 KT-88's each. All pieces have been significantly upgraded by the original designer, and sound terrific. They also use and waste a considerable amount of energy, occupy a lot of real estate on the large audio rack which I built, are visually hardly the most beautiful of black boxes, raise the temperatures in the listening room at least 10 degrees, and cost big bux to retube.
What OP says resonates with me as well: "I like the idea of keeping hi-fi compact and with high performance without betting (sic) just big and power hungry."
Increasingly, I've become very intrigued with the idea of going to either a fine integrated SS, or, if I were to keep the tube pre-amp, replacing the tube mono amps with one or two class D amp in the interest of "streamlining" and efficiency.