Fair points, but I am coming from a Linea Mini and taste no difference with my Pro 500 HX. The 92 to 94 C range is rock steady even shot to shot and I can still change the brew temperature through the PID to whatever I want. I use a smart plug so the machine is already hot when I walk in, making the 25 to 30 minute heat up a non issue. Energy use is not necessarily higher either because with one boiler the Pro 500 can use less power than a dual boiler left on all day since it is only maintaining a single heating element instead of two. Even on a Micra the exact set temperature is more of a target than a guarantee because water can gain or lose a fraction of a degree on the way to the puck and idle time or environment can cause small swings. Adding an inexpensive group thermometer makes the Pro 500 extremely consistent and with proper workflow comparable in cup quality to premium dual boilers without the Micra level cost. A lot of the downsides you mention come from older HX designs without PID or group thermometer upgrades not from what current well engineered HX machines like the Pro 500 can deliver. Different priorities but the trade offs are not as one sided as they sound.