1st off, I LOVE rome. As you can see by my name. lol. So anyways, I've owned 5 artifacts, and they're my favorite board ever. It completely smashes all the rails I put her on. No doubt about that. As for the garage rocker, it seems like it's not quite made with the same materials. My friend owns one, and he said he wishes it wasn't as stiff. I've never ridden it though. I actually just emailed Rome the other day. I want a new rome board, because that's what I ride, and didn't want the artifact because it's a noodle on jumps. They said that they suggest the reverb rocker for me if I want to hit small jumps, but still kill like the artifact does.
All in all, with the artifact, you won't regret a damn decision.