.023 vs. .o30 for sheet metal

[Cobra06]

There seems to be much difference of opinion on which wire is best for sheet metal. I've always used .030 and it works for me. I use Harris 20G in My Lincoln 135+ (hate the soot but it works) and .030 in my MM 210. I am tempted to try .023 wire, but before I go out and buy a new liner, tips and wire , was wondering about the advantages if any. I know much of it is personal preference, just curious. From the technical stand point, what I've been taught is the larger the diameter the higher the minimal current is needed, and the penetration decreases.
David