As reported by LeftyE, Success Pond Road is in pretty good shape.
Miles 0-3 have been recently graded, the initial hill is a bit washboarded and covered with small rock, but not an issue, the rest is in better shape than a lot of paved roads by me...
Miles 3-6 were a bit rougher, with some boulders sticking up here and there, but all easily dodged on one side of the road or the other. One minor ditch/bump that low-clearance cars will want to slow for, but won't impede progress. Also a culvert with one end exposed (now in a serious ditch, and also marked off with a cone and some flagging) that was fine on the other end.
Miles 6-8.1 (my trailhead today) were in good shape. Some spots out past the 3 mile mark seemed to have had some spot-grading. Overall, I was able to comfortably average nearly 20mph in my low-clearance car (25min to do the 8.1mi), versus the barely 10mph I was able to maintain last year at this time.
Active logging appears to have been going on. Several loaded logging carts staged at the start of the road, and a few more on a side road a ways in. No work going on on Saturdays I guess? The road is fairly easy to find if you use the AMC description and watch for the ATV Trails signs from just South of Berlin over the bridge.