I am using a Ki-tech right now. It's consistently soft throughout the tip and doesn't seem to mushroom much.Straight out of the box elkmasters are the softest tip you can buy. I don't know if I would recommend an elkmaster that hasn't been soaked and pressed, but those play more like a medium/medium hard (Which I absolutely 100% love). Triangles I think are closer to medium-hard straight out of the box.
I think if you want a non-layered medium soft tip, probably a ki-tech by outsville.
A LePro is med/soft right out of the box, and they play great.
Elkmaster tips are awesome.
Just squeeze them down in a vice to your desired firmness.
One of the most versatile tips ever made.
Milk duds play great too; when properly made.
They're one of my favorite.
Triangles are nice as well,
but a pressed Elkmaster just feels like magic.