Here are a few snapshots of the "BLACK Hard Rubber Case for Motorola Droid A855" I bought on ebay a week ago. I've never held a Seidio Innocase in my hands, but it seems to have a lot of the same features: slim form factor, soft touch rubberized coating, and no movement on phone.
The fit seems to be excellent, and while the coating is comfortable, it's not as grippy as something like the body glove case. That's good for me as I often carry my phone in my pocket and it doesn't drag my pocket completely out, though it's not as slick as a naked Droid.
I'd have to say it looks identical to the Amzer case, though without the logo. It was $6 shipped when I bought it, but it now seems to be $10. Still worth it, IMO. I don't want a logo on my case!