I re-rode the Camp Chase Trail from its eastern terminus to Battelle Darby Creek Metro Park today, and rode the section from there west last year. It's a nice trail, in good condition, and the gaps have been filled in over the years. Of particular note is that the gap orangedoug mentioned, at the Metro Park, was closed in March of 2020. It is a bit difficult to find the connection through the park from the west though; go to the roundabout at the west end of the parking lot, and find the trail branching off southwest (which would likely be the last direction you would expect to find it), and that's the connector, with an Ohio to Erie trail marker hiding in the woods.
I rated the trail 4/5 instead of 5/5 because while it is in good condition, it's the least scenic of the "big 5" trails in Columbus. I ride the Alum Creek Trail and Olentangy Trail every year; they're beautiful. Comparing this trail to the Alum Creek, the major difference is you forget you are in a city on the Alum Creek Trail. On the Camp Chase, for the first 7 miles going west, it's almost all city (there is a park area near Wilson Road). It does open up and become more scenic past Georgesville Road. Realistically, the section east of there is a "every few years" trail for me.
Parts of the eastern section were also reminders of the increasing poverty in parts of west Columbus since the pandemic; tent encampments were set up along parts of the trail and the parallel railroad, which hadn't been present the last time I rode the trail in 2020. In the afternoon of one of the first warm days of the spring, it didn't feel dangerous, but if you're planning an Ohio to Erie trip and aren't from the area, plan to be Downtown before sunset. At least the trail seems to be of use to the residents living by it; several tents had bikes by them and one man was working on his bike from the tracks when I went by in both directions.
The Hilltop Connector to the Scioto Trail at the eastern end is not a bad connector at all. Road speeds are moderate, most of it has a dedicated bike lane, and even at rush hour it didn't feel risky (and I'm not someone who rides roads).