6-8 oz is a little high for ten plants with only 1100 watts. Put your buckets in rows of two side by side and get that light up off the floor. You'll get better light penetration and more overall light will be taken in because the plants aren't spread out. If you look at you set-up you'll see that directly under your main light is nothing but another light and vis versa. Also you have no hood reflector so the bulk of your lumens are being spread out among the room and not directly on your plants where they should be. Daisy chain the two lights together above the plants and line them up in rows of twos. Also try and get a few hood reflectors, nothing fancy but something to reflect all those lumens were they need to go, the plant. If you wanna get over 4 your gonna have to veg another few week and use some type of nutrient that is specific to bud site production. Maximize your root growth with root exculator and your bud sites with your choice of nutrient. Do these things and you may be able to get close to 5 per plant on some. They do look healthy and nice and bushy. Like hydroburn said, your gonna need to fim or top to produce some more main colas and sights. You seem to know what your doing pretty much so im sure you'll get a decent yield regardless.