I checked D20 Modern again lately, and I could see that there were a lots of classes that were just not worth playing. The Personality for instance. I managed to find a system to try to solve the problems with basic classes, by using special Gestalt rules.
1) Fast is excluded from Gestalt.
2) Strong hero can gestalt with Tough, Smart, Dedicated or Charismatic Ordinary classes. The choice is made when the 1st level is taken. (A bit more HP with Tough, or a bit more skills and will save with the rest, with the very distinct possibility of playing combat medic).
3) As Dedicated Heroes have some decent fighting ability (3/4 BaB, decent defense), 2 good saves, and one of the best skill lists in the game, they can Gestalt with Smart ordinary or Charismatic ordinary to expand their skill list and be closer to Fast heroes, but stay stuck with their D6 HP.
4) Smart and Charismatic heroes gestalt with Dedicated Ordinary. A bit more fighting power with the BaB, and survivability with better Defense and Saving throw progression.
5) Tough heroes can gestalt with Dedicated or Smart ordinaries for skills points, skill lists and will save (that's all they would gain, really).
So fast stay damn untouchable by ordinary attacks (bullets, explosives, melee), keep a good skill list and good skill points, but would be a bit lacking in special defenses (poison and spells/psionics).
Skill types wouldn't stay sitting ducks, and Strong, dedicated and tough would be all around more efficient, while not being as much of a Touhou protagonist than Fast hero.
So far it sounds good. But what about advanced classes? Then, I would need specialty classes that are made to Gestalt with classes groups (offense, social, specialist) to allow them to be attractive options, since most of the advanced classes that aren't made with the fast hero class in mind and aren't spellcasters/manifesters are a bit lacking in useful and interesting attributes.
Thank you in advance all!