Well, I just have to throw in my P7 opinion:
The BEST manual of arms invented is on the P7. A single lever, cocks, decocks, releases the slide and acts as a drop safety. And it's all ambidextrous.
The only shooters that require "special training" are the ones who are un-learning old habits.
The P7 avoids all the following classic pistol problems:
1. Crunch and tick. No heavy first shot or transition ala DA/SA.
2. Light trigger/no safety accidental discharges ala Glock.
3. Manual safety fumbling. Big ambi lever, not small thumb switch ala BHP and 1911.
4. Heavy trigger blues ala DAO.
And it does all that in a smaller, more accurate, completely ambidextrous and reliable package.
It is not necessarily a perfect choice for nasty combat conditions, sand and salt water could be a problem. Of course, sand and the M9 seem to be a problem, too.
The Glock is a fantastic $350 mass issue pistol. It gets questionable what you're getting for $600, though.
As an aside, I would never base too much on the US military weapon selection process. Let's look at their track record:
1. Select fire M-14 instead of the FAL or AR-10
2. M-60 instead of just about anything else
3. M-16 instead of AR-18 or Stoner 63 rifle
They haven't really picked a winner since the M1 Carbine
PS: You're on crack if you think the cocking lever is hard to hold in. It takes a pound to hold and can be accomplished with your pinky.