did you mean mane and tail or MTG (mane Tail Groom), because mane and tail is shampoo and conditioner (as far as I know), and MTG is a growth aide like Mega Tek....
as far as Mane and Tail, I like it as a shampoo and conditioner, its one of my staples.
As far as the growth aids:
I havent used MT since last summer, but I didn't really give it a chance (only used it for about a month) but I'm going to give it another go around since I have it.
MTG seemed to work for me several years ago as a growth aide. I kept it up for several months and it seemed to get me out of a rut. stopped using it because it was too much upkeep and messy; the back of my neck broke out because it would run too much and it made my hair too oily wich limited what I could do to it. Once I put it on, I basically was confining myself to my home because I was too paranoid of the smell and dripping oil. I loved the results and would use it again if I used it nightly with baggie treatment, co-washing daily and wet bunned as my daily style. (hmmmm.... maybe i should revisit it after I finish up my MT)