My first ever grow is just winding down and I find myself really enjoying what I was able to produce. In just a short time -80 days- I grew three Northern Storm auto fems from seed to harvest. (Plus another week on the rest of the harvest after removing the colas today.) From that I think I'm going to end up with around 3.5oz or more dried & cured. While not fantastic compared to some hauls I've seen reported around here, for the small space I have I found it acceptable. Plus I have some no-name bag seed plants just shy of 3 weeks into flower. I really like the simplicity of the auto fems. Start it in it's final pot, nurture it along and don't worry about the lights nearly as much. And starting a next run with autos would let me do that as the current run is winding down without having to have separate veg and flowing spaces. BUT! And there is always one... I know I can get much better yields from photo period strains. Or can I? In my space (approx. 3' x 5') with a 600W MH/HPS light, what can I reasonable expect from about 3 plants at a time? Maybe 4. I guess too my title is misleading as I ordered a few more Autos the other night. Cherry Bomb Auto, Amnesia Haze Auto and AK 49 Auto.
1/2lb on the low end and over a lb on the high end for a 600w light has been my experience. My lights always take up a 4x4ft. area though. Do what you are comfortable with...sounds like you are just getting started and meeting your expectations. You will get better with experience.
My flowering chambers setup is the same as yours with dimensions and light. I average 13-23oz per 60-70days each room(each depending on strain). This is perpetual, with 60-70 day veg, DWC, Fluxing, Bonsai, supercropping, and then SCroG is introduced on the flip to 12/12.