one more thingto keep in mind, and this is important. TIG= you have 3 things going at ones, nd it has to be in harmony. one hand - torch , other hand filler material, one leg remote foot pedal, for power output, ( yes it can be hand controlled as well) it takes some time to master the 3 things going at once. on a flat table , pieces laying flat makes it easier. anything out of position or you are not sitting on a chair operating a pedal makes it much harder.
MIG= none of the above one hand operation in any position. reaching into the corner , upside down , down side up does not matter.
to comment for the fella' that mentioned STICK welding. slag , slag inclusion, and spatter, and a LONG stick electrode makes it undesireable for me. and for an average home / hobbiest its usage would be rare, most places that have a good quality high output MIG placed the stick machines in the corner. in an average shop setting MIG over taken the STICK machines nowdays Stick dominates field operation only, and may be some special interest.