I didn't blast Gen2 for consecutive days when I had them before cos' that time, it will auto trigger back to auto mode. Probably app / firmware issue. Gen1 no issue. I only operate at mid speed when I had them. No issue. Hi speed especially Jet mode is too noisy. Jet mode - probably will feel anytime might give way.
I had tested on my Pro. Blasted for consecutive 3 days 24 x 7. No smoke coming out.
After that, every night till now, have been switching on (Favourite mode). Day time on standby mode (didn't off the main power supply from wall socket).
Till date, no sign of weakening. Motor still going strong. Unlike my previous AX40 (made in Korea), after several months, the fan speed weakens as compared to another new AX40 set. (Despite changing to a new filter). Maybe I had a lemon set ba.
Anyway, the point is, XiaoMi purifiers are reasonable durable imo. How long will it last, I also dunno. So far so good. Previously I also sceptical about China products.
But not for purifiers.... XiaoMi purifiers good enough for me. Valuable and works well.
But of course Pro is the most expensive. So worth or not worth, depends on individual. Gen1 / Gen2 does its job relatively decent and good too. Anyway, filters are interchangeable. Can use in any of the 3 models.