The green tide army does indeed work. it is a hoot to hear your opponent say that they don't have enough firepower to kill all that
I know it is a bit of a chore for the movement phase, but with the run you can usually be in charge range on your turn three. Now being orks, it is about target saturation, that is; give your opponent too much to shoot at. Not to mention that if you are concerned about taking off handfulls of models every turn, then you are playing the wrong army.
I have run the green tide a few times, (don't tell anybody, as it might ruin my speed freak reputation) and with it took out the infamous Space wolf thunder cav list, the insane BA death company list, and even out hoarded a tyranid list. It can be done.
As for the enemy getting behind you, unless they deep strike it won't happen, as the green tide covers the board from side to side with no gaps for any enemy units to get through.
Personally, I am not a fan of the storm boys. I found them to be overcosted and very inefficient for their supposed roll in the army. In fact the large unit I did have, I got so mad at them that I traded twenty storm boys with boss Zag for some bits and a gift certificate. Some people say they have had some luck with them, but I haven't met any personally. I would hate to see you lose your love for orks just because of your choice in a naff unit.
Beef up the boys squads, add in some firepower like lootas and or grot guns, and practice yelling "Waaaaggh!" and you will have many enjoyable games. Remember, orks are not about the hero, orks are about the mob.
My two teef.