Basically all vitamins are good. Whichever manufacturer you choose, the raw ingredients are common purchases and they come from the same suppliers everyone uses. The difference is how they are made, and how they are marketed. A company like GNC, or Vitamin Shoppe use good manufacturing practices so quality and purity are generally never an issue.
When a company decides to make a "Mega-Men" formula they select from products they already make, in this case they package them up in cellophane packs. Each cell-pack may contain more than one pill or tablet. They could have probably fit everything into fewer tablets, but that adds to their development cost.
A company like Biotrex attempts to create formulas and put everything you need into one easy-to-take tablet.
If you can actually "feel" the improvement in yourself, then it sounds like you found an agreeable product for you.