Stresam(aka etifoxine) is a benzoxazine and works on the beta rather than alpha subunits on the GABA-A receptor. It produces benzo-like anxiolysis at 50-100mg dosages with some slight relaxation akin to l-theanine as well. The anxiolysis is comparable to a benzo but it lacks any recreational effects. If you were to take 200 mg my guess is there is a ceiling effect to just how much anxiolysis and relaxation it can cause and you would probably just get increased risk of adverse side effects such as a headache, vertigo and if you're really unlucky hepatoxicity.
Use it as a tool to cut down on the hardcore-mild(bit of an oxymoron there) tranquilizers like benzos and barbs rather than chasing after a high. A major tranquilizer like some neuroleptic would make you feel more fucked up than etifoxine ever would or could. It's a fantastic tool for dealing with stressful situations where you don't want to take a Valium or something because you only allow yourself so many of them per week.
Use it as it was intended to be used, don't abuse it to try and catch a buzz! The few reports i've read online where people have abused it by taking more than the recommended dosage all relayed the message that the experience was underwhelming and not worth the time.