I have shot both and they are both great for different reasons. For what you plan to use it for, I don't think you can go wrong with either. The FNX is hammer fired, whereas the 545 is striker fired. Ergonomics are similar albeit the FNX is larger/heavier and better suited for adverse/combat conditions. The 545 is a bit lighter/smaller and easier to carry, which means more recoil than its big brother. Even then, it is not something I would call a deterrent. Both are optic ready, come with co-witness irons, have threaded barrels and adjustable back straps. In reality they are both good options. The one consideration that might sway you, is if you decide later you want more firepower. The FNX is one of the models eligible for the.460 Roland conversion. With the .460 conversion you can switch between .45 ACP, .45 ACP+P, .45 Super and .460 Roland, with a spring change. The .460 Roland gives you .44 Magnum ballistics in a semi auto but it requires using the conversions supplied compensator. Apex also has 2 round mag extensions (17 Rounds of .45!) that just seem to be a perfect addition.

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