350 degree is OK. I worked at a SMD assembly line and the time between set up the machines we repaired PCBs (SMD and THT). The 350 degree was confirmed by the QA-dept, they made many solder test with many different temperatures, tools etc.
From my point of view it is more important to have a solder iron which control the temperature. In this case it is not important how many Watt you use, because you can use a maximum temperature. It reduce the risk to give to many heat to the parts and PCB.