Baclofen put me out like a light. Phenibut, an OTC supplement with a very similar chemical structure and mechanism of action, also worked very well for sleep, but left me kind of groggy and hungover the next day.
Tolerance does occur to the sleep-inducing effects of phenibut (don't know about Baclofen), and it you become dependent on Phenibut, nothing else in the world except Phenibut or another GABA-B agonist will help you sleep. The rebound insomnia is profound. Use twice a week at most, cycle with other sleep aids if insomnia is more than twice weekly.
"Tolerance to the anxiolytic effects (of BZD's) probably does not occur"