G9i at Marshall Street
G9i is an older plastic Gateway used that molded up very flat and very stable in Wizards. It is a very firm but very grippy plastic (for a firm plastic). Recently Dave at Gateway acquired some more of this plastic (is it the exact same, eh) and reran Wizards in it. For a firm putter lover like myself, they are a dream. I will say that they've gotten even better with use too.
The most recent (re)runs caused quite a stir, but many lost interest when people reported theirs beating up and chunking pretty bad. Mine have taken a beating, but I haven't noticed any serious damage like the others. Most Wizards take a lot of damage early on and then seem to just stop showing any more in my experience. In an attempt to improve durability, Dave started messing with the blend, and I don't know what happened after that as I bought a pile from the first runs and the DGCR group buy (first or second run, same stamp but different colors and placement). I heard they weren't as flat, but I never stuck around the threads long enough to see how stable they were. As always, if I have any info wrong, please someone correct me.
There are a couple threads about them in the Equipment and Marketplace forums. Look around for them if you want more info about them. The threads stay on topic fairly well.