wow, there is a lot of wrong information out there about MG. People just believe what other people say with out asking any questions or for proof. MG soil has water soluble nutrients in it. That means every time you water your plants, you give them food. The trick with MG is to not over water your plants and you will do just fine. My first grow was in MG and they were healthy happy plants once I got my waters PH under control. As for MG pot having a bad taste, well that's just false. Learn how plants use nutrients and you'll realize that flushing is a myth. You can't pull nutrients out of your plant by giving it just water, it just doesn't work that way. Since MG nutrients are water soluble the legendary pre-harvest 2 week flush won't help anything. In fact it'll only make it taste worse if you are so inclined to believe that the nutrients are stuck in the bud and your smoking them.
Trust who you want, but take your own experience over others advice. Try leaving one of your plants in MG if you plan on switching them all to FFoF and get your watering schedule under control and compare it at the end. Try not flushing one of your plants and see if it makes a difference to you. BTW FFoF is an organic soil, where as MG uses salt based nutrients, so if you do transplant into FFoF try and get as much of that MG out of there or the salts and urea and harsher chemical nutrients will kill of your soils bacteria and be counter productive to switching to a organic soil.
Hope some of this information helps out. Happy growing.