I have shot 3 of the 4 guns listed so I can give my opinion on all exceept the Taurus. If I were to take the Taurus off the list I would replace it with a CZ P-01 which is comparable to the FNX-9 and the Sig 229 as far as quality goes. The XDm 9 is a nice weapon that is very popular and a very good shooter. it is loaded with safteys and gizmos and hold a lot of bullets in the mag. It is a good gun that would serve you well. I have heard of very few unhappy XDm owners and even fewer function related problems.
The FNX-9 is the new version of the FNP-9 which actually is the weapon my friend has and that I shot regularily. I like it a lot. It points naturally and fits my hand great. It does not malfunction and makes holes right where you want it to make holes ....consistantly. A real good gun! I like it. I would not hestitate to own one myself.
The Sig 229 is a very tried and true gun it has the accesory rail and a DAK trigger system A very nice trigger in comparison the XDm IMHO. The sig is a great gun! It is my first choice of the ones I have tried on your list. It is a very nice looking gun and it is accurate and the second shoot is on target very quickly because the recoil is very manageable on the gun. Sigs are easy to get work done on but rarely need it.
The CZ P-01.....If I could only keep one gun and had to give up every other gun I own I would keep my P-01. It is a wonderful and reliable gun to own. It points great it shoots great it only holds 14 rounds but it is a great gun to have and a accurate shooter to be sure. It is my favorite 9mm bar none.
All of the above mentioned guns can be fit with night sights or lasers if that matters to you. All are easy to break down and clean which I suggest you do before you shoot your new gun. I like the hammer gun but own a few striker fire weapons and don't have problems with them i just prefer the hammer guns.
Good Luck you have a very good selection chosen. I hope you are very happy with your choice. Shoot often be safe and have fun.