My YH fills my 45 minute SCBA bottle about once a month, normally to 300 bar. It's been doing it for about 2 years. I had to replace an O-ring near the reed valve once. I change the oil (I use Nuvair 825) once a year. I added an inexpensive radiator and a couple fans meant to cool computers. I use distilled water with water wetter in it in a sealed system. In the summer I put a couple soda bottles of ice in the water too. Normally this lets me fill from ~3000 to ~300 bar in one run less than 20 minutes and with a head temperature around 60 C. I also added an extra filter for the air that comes out that I filled with temperature change dessicant.
Minimum change in my opinion is the extra filter for the air and the "good" oil. Extra cooling helps fill a bottle in one run with the temperature well under the 70 C limit.
I don't fill my guns with the YH, I quit that when I got the bottle. It is noisy but I can tolerate for about 15 minutes to get 10-12 gun fills.