How tall...? Depends on how long you veg, size of pot, strain. (sativa's generally get much taller than indica's...hybrids somewhere in between)

High or stoned...? I'm guessing it's the difference between a 'social' or 'functional' high, and a 'couchlock' or a "fuck-you, I went and got the ice cream last time" high.

500 g/m2...? 500 grams per meter squared average yield, if using their techniques, nutes, lighting, and their fuzzy math. Usually on the generous side of the equation, and unlikely you'll match it without some extensive experience.

Plant yield depends bunches on strain, genetic quality, growing medium, nutes, temps, humidity, your experience and patience levels...just to name a few of the factors.