I recently set up a Kim Steele table from the early 90's. It had been in storage for about 8 years, which always raises concerns for deformation of the slates. However, despite me having never previously seen a SAM table, the frame assembled easily, and the slates leveled out better than any Gold Crown that I've ever worked on. The leveling system was a bit quirky, at first, but I became a fan of it.The humidity/temp affects the cloth/rubber more than anything else so frame material really doesn't matter. The frame of a quality wood-framed table is just as stable due to its mass. Humidity is not going to make a GC frame move. You guys need to talk to RKC about SAM's, he's worked on them and can tell you from a mechanics pov their issues.
My only complaint is the rail design.. They are thin gauge steel, and are very light and hollow. This required additions of wooden strips, in order to staple the rail cloth. Also, the featherstrips are very thin plastic, which breaks very easily. It also seems to be impossible to find readily available replacements.
That said, I am very impressed with the way that the table plays. I enjoyed it so much, that I stuck around for a couple of hours, playing one pocket.