for S&W stainless steel, or even blued guns.

Anyone have personal experience with this?

Looking to take out some fine scratches on the stainless or basically make it look as new as possible.

Thanks.

Stainless...Yes.
Blue....NO. It'll thin and strip bluing.
All metal polishes, no matter how fine are abrasive. Use them a little too hard or too often and your blue will be thinned or even removed depending on how hard you rub.
MAAS, Mothers Mag, and similar are too abrasive for blue. Even Flitz can damage bluing in short order.
For blued guns clean it with a solvent, then apply a coat of a good wax like Johnson's Paste or Renaissance Hard Carnuba. NO car wax, many are abrasive to clean paint and will damage bluing.

If you use it on stainless, it'll make the areas polished shiny, so it won't match the rest of the gun.
If you want a shiny gun you can do it by using a metal polish.

A way of removing light scratches from a stainless gun and keep the factory look is to go to an automotive supply house and buy a few different "grit" Scotchbrite pads.
These are synthetic abrasive pads similar to the green pot scrubber pads sold in grocery stores.
These come in finer grades than the pot scrubbers.

To remove light scratches, rub with a pad that most closely matches the original factory grained finish until the scratches are gone, or at least less noticeable.
Deep scratches will require professional level re-polishing to remove.

Finish by "stroking" the pad in the same direction the original grain ran.