I've never worked with a myco bag, so I can't comment there, but as to spore syringes; one syringe can yield a LOT. When I get a syringe, I inoculate 8-10 pints of liquid culture (made from corn syrup and water). Assuming that my sterile technique is good and the syringe is not contaminated, every single LC will colonize over the next 2 weeks. Once there's nice robust mycelium growth in the LC's, I use those to inoculate grain jars. There are 473cc (or ml) per pint jar. I use between 2-3cc to inoculate a quart jar of grain. 473/3 = ~157. That means I can make over 100 quarts per LC. I spawn my colonized grain to coir/verm bulk sub (and occasionally add some coffee grounds for increased nitrogen) which stretches each quart of spawn to ~2 or 3 quarts of substrate. As far as actual yield in terms of mushrooms, it varies when using LC/multispore syringe because there are a ton of competing substrains in the syringe (thus in the LC and grain and substrate). Figure your dry weight of mushrooms, under pretty ideal circumstances will equal the dry weight of your bulk sub/spawn.
As to cubensis strain, I've enjoyed growing B+ and chilean. I'm currently growing tapalpa and its coming along very nicely. Essentially, all my cube grows have looked pretty much the same. Remember, the size and whatnot will vary a LOT when using multispore. For example, the first 3 oz dry I've gotten from this grow have been between a few cm long to a 2-3 inches when dry. I currently have a tub that is putting out monsters, each easily over 6-8 inches wet (the others were max 3-4 inches). I didn't change anything for the grows, same lc, same substrate mix, but I assume a different substrain won out in this batch and it's a monster. If I was really serious about this/not moving around frequently, I would cut some tissue from these monsters and use agar to isolate the substrain so that I could consistently grow these monsters. If I unpack my camera tonight I'll shoot some comparison pics so you can see what I mean. :d
