Full length guide rod opinions vary. I prefer a full length in my P-13s. On the plus side are:
1. Prevents recoil spring kinking. (main reason over the traditional two piece design)
2. Additional weight in the front to absorb muzzle rise.
3. Ability to vary weight- stainless guide rods, tungsten, or even a Hartts recoil reducer.
On the minus side are:
1. Disassembly is a little more complicated.
2. Additional weight to the gun.
Hope this helps!
