I'm not sure where Ultimagabe's experience comes from, but it's the exact opposite of my experience. I've been playing a 3.5 Eldritch knight since 3.5 came out and one thing's for sure: my character has never been called weak. Losing two caster levels is a significant sacrifice, that's for sure, but if you actually use those weapon proficiencies and the synergies that wizard has to offer for melee combat, you can make those two levels pay for themselves pretty definitively. If you decide to shift the balance of the class by allowing it at the loss of only a single caster level, it may well stay balanced for people who want to play their eldritch knight like he was a straight-levelled caster, but it will be a pretty significant increase in power for people who play the class as a heavily magical fighter.
My experience--as well as the fact that the PGtF militia feat came out well after 3.5 and thus was not anticipated in the design of the Eldritch Knight (just like the ur-priest, etc exploits were not anticipated in the design of the Mystic Theurge)--leads me to believe that allowing the militia feat alone to qualify a wizard or sorcerer for Eldritch Knight would be a mistake--not as big a mistake as letting wraithstrike into your game, but a mistake, none-the-less.