Problems with A/C

Pressure on 134 always runs a good bit higher. I don't know where "the pressure is good" comments are coming from. I've done A/C work since the late 70s. Done literally hundreds of 134 conversions and I always end up with 30-50 on the low side and 300-350 on the high side. I hardly ever pay attention to the amount of refrigerant. I go by the pressure on the gauges and it cools good and works right every time, unless there's another problem somewhere in the system. Also, 134 will never cool like 12 down low at idle. It needs some RPM on the compressor to cool as good as it can. I've seen people complain about new cars regarding that, but there's not a lot you can do. It is what it is.