I have 7 gold tetras! I bought them from a tiny shop in Chinatown; I'd never seen that breed of tetra before, so I bought them all. So far, they have been great--very peaceful, none have died. They are bigger than neons, but not by much, and have thick bodies like neons. Mine are not especially active compared to some of my other tetra species. They share the tank with cardinals, rummynose, zebra danios, harlequin rasboras, and a pearl gourami. I recommend them!
Cardinal, I have also read that the gold color is caused by a parasite. I have no idea whether it's true. Mine have remained gold.
I have two Penguin Tetras who are magnificent and I'm dying to get my hands on at least 5 more to make a proper school, but I can't find any. The two I bought were the last two in the tank at the LFS.