Classic radio ^I have a QRP rig, but it is the old Yaesu 817 I have had for the better part of 20 years. QRP was my favorite power of transmission, as it really tested your ability to get the SWR down as close to 1 as you could get it by exact trimming of the dipoles of the antenna. Doing digital modes on QRP was a fun hobby, too. Amazing how far 5 watts on a good propagation day could get you running PSK31.
Wouldn't say I'm heavy into QRP, but I know it definitely stretches your Engineering skills to get it to perform well, and is valuable training for true SHTF scenarios.
I tend to stay with voice, but the digital modes are impressive. A long-retired Canuck Military buddy of mine (also a ham) commented a long time ago, that these AR digital modes often reminded him of the signal-processing for hunting subs...... similar math, different targets. FT8 seems very popular today, and soon I can have my AR AI avatar talking to yours 24x7x365 (not my thing), but again, pushing digital signals that far @ low-watts is impressive (the guys in a park, running FT8 @ 100 watts do crack me up), and I do see plenty of people firing up FT8 short-term to test propagation or a new antenna quickly.
Fun hobby, with no end of projects to keep busy with....
Rgds, D.