There is a mantra that TIG+SMAW (MMA) has superior quality compared to FCAW in Pressure Vessels and in Water Boilers applications.
This sounds really sceptical to me, considering that all three welding processes give melted metals. Especially since there are Basic and Rutile Cored Wires, just like Electrodes.
I think FCAW is the way to go in the workshop, especially since you have greater welding speeds in comparison to TIG.