The Traillink information is a little dated. The official Folsom site lists this trail as being 50 miles long, which is accurate but misleading. There are at least 50 miles of trails but it's a bunch of interconnected short trails and not one long route.
These trails are the craziest maze of paved trails I've ever been on. There are very few signs telling you where you are or which way to travel to get to a particular section or street, so if you decide to ride this trail take your GPS with you and a copy of the bike trail map or you will get lost. I took my family during the summer of 2017. We had a GPS and a printed map and we still took several wrong turns.
Even though you're probably going to get lost, it's well worth the trip. The trail meanders through apartment complexes from time to time, but you're generally surrounded by great scenery. We passed several ponds and creeks, and crossed over several scenic bridges. Folsom is a bike friendly community, and is safe enough that we weren't nervous after dark. If you can figure out where you are, there are plenty of places near the trail to get a meal. We found a few restrooms along our route and used the GPS to find food. Restaurants with outdoor tables and bike racks are a common sight in Folsom.
There aren't any towering hill climbs, but there were a few segments that were steep enough that I had to tow my five year old. If you're traveling with toddlers you should talk to a local bike shop to find an easy section. We didn't encounter anything that our nine year old couldn't handle.
I live near Discovery park, which is where the American River / Jedediah Smith bike trail starts. That trail connects to this trail system somewhere around mile marker 25. I usually pedal from Discovery park with my kids, so I don't think I've pedaled more than half of what's currently available in this trail system. As a result I can't vouch for every inch of it. However, the sections I have traveled are good enough that I would not hesitate to drive for three hours to come ride this trail if I wasn't local.