So you're saying you have a PCH912 and a Resin Pilot Falcon in your possession and you have to choose one to keep?
With Anser's answer in mind -- which is more important to you? The line variation or the pen?
If you got a resin Falcon I recommend returning it and getting the metal Falcon! Considering most resin Falcons sell for around $140 and you can get a Metal Falcon for $180 on eBay --- the 22% extra is totally worth it. I replaced one of my resin Falcons with a metal one and it's so much better I have to sell the other.
Here are some notes:
PCH912 - fatter body, heavier pen. 16g. A very nice weight. Feels great in the hand. Slightly longer nib than the Falcon. One less metal ring... but it has a metal interior in the section. The nib is easily removable - simple friction fit. This is nice. The feed is normal, it has fins. One negative - it has a plastic discs at the top of the cap versus the Falcon's metal disc. Interestingly the body of the PCH912 is a few MM shorter than the Falcon's body - but when you add the longer nib it's a longer pen overall. Standard sword shaped Pilot clip. Takes (and comes with) a CON-70. This is nice - 2x ink capacity vs. con-50.
Resin Falcon - thinner, slightly longer body (shorter nib.) 10g!!! It's so light you can barely feel the Falcon in your hand. (For comparison the metal Falcon is 19g.) The clip has a sext modern curve - nicer than the 912's clip. Interior section is plastic. Nib is difficult to remove - I can't remove it. The feed is neat - it has no visible fins... The metal disc at the top of the cap is nice.. It's a good pen but it's just so lightweight. And it only takes a CON-50 sized converter (or con-20)
As far as the nibs go... I don't have a standard Pilot soft nib so I can't compare. But as Anser put it - the Falcon probably wins.
So your situation is tough.
If it was me I'd return them both and get a Metal Falcon.
If you're just keeping one? I'd keep the PCH912 because it's a pen that will feel nice longer. For me - every time I used the resin Falcon I just felt that it needed more weight. Pilot shouldn't have made a smaller pen for the Falcon nib. They should have made the Falcon nib available on the Custom 91 which is also a superior body to the resin Falcon.