Is one more easy to weld for a beginner? MIG welder, not sure about the specs on it.

Any weight difference? Strength difference? How much shorter of a life will the mild have?

Simply put, it's relative to your settings on the welder. I don't remember there being much of a difference welding either/or. Though I also do not do this for a living.

If I can remember, the stainless needed slightly more power to get everything to weld.