I like the flexibility of TIG, I can easily switch between mild steel
and stainless, different thickesses, etc.
TIG is a challenge when it's difficult to get the electrode and rod
where you need it (e.g. the inside corner where two pieces of angle
iron meet to form a right-angle corner). And the footpedal is a pain
unless you are sitting down. A hand control is easier if you are moving
around or standing up.
If the goal is to quickly and easily put things together, MIG is better
Best of luck.