Well I was on it daily for up to 80 mg three times a day for muscle spasms that did not respond to any other drug (can't take cyclobenzaprine, the zannaflex didn't work, in the doctor did not want to raise my Diazepam dose high enough to work), and it caused horrible insomnia even during a taper. AS WELL AS CENTRAL SLEEP APNEA. If you don't know what that is, be glad. It is where the body and brain are disconnected right at the point of sleep and you literally stop breathing as you transition from wake to sleep. It happens to a non-trivial percent of baclofen users enough that it's identified as a side effect.
Ultimately, the doctor raised my diazepam dosage until my condition resolved with respect to the severe muscle spasms.
I will never touch baclofen again, but I will take Valium and Librium no problem.