Which is a better pistol M9 or the M1911?

They both have advantages and drawbacks.

M1911:

• More powerful cartridge
• Less magazine capacity
• Single action only design
• Frame mounted safety allows it to be carried "cocked and locked"
• Heavier recoil

M9:

• Less powerful cartridge
• Greater magazine capacity
• NATO standardisation of 9mm cartridge alleviates supply issues which might exist if the .45 ACP continued in US service
• Pin block hammer drop safety does not allow for carry in a "cocked and locked" position. Early models of the Beretta 92 had a frame mounted safety - similar to the M1911 - which allowed for this (this feature is retained with the Taurus PT92 pistol).
• Single and double action
• Trigger sits far forward when decocked, and this has been an issue for soldiers - particularly those with smaller hands - when trying to fire the pistol in double action mode.
• Original magazines ordered for the M9 pistol were non-OEM, and proved to be problematic.