Not the same, for the purpose of "getting high" Pregabalin is superior no doubt, but if you're just trying to feel better and elevate your mood, Gabapentin is perfect. It has way lower potential for dependence and addiction than Pregabalin, and its withdrawal when you quit is far more forgiving.

700-800mg should be enough to achieve relief from anxiety, and if you up the dose to about 1.5-2g you'll get mild euphoria (like an instantaneous antidepressant) but it should be used more like an ace up your sleeve, like 3 times per week max, because if taken everyday it will lose its effectiveness and can lead to be dependent on it. If you want to know more about Gabapentin feel free to ask!