Funny you should ask!
I just finished fletching a dozen 2016s for the first time with Gateway feathers. I liked them fine. I have always used Tru-Flights, but the local shop had the Gateways in the color I wanted.
I could tell a slight difference in the two but it is hard to explain, I guess the Gateways seem a little more "stiff" and like Night Wing said, maybe a little more durable?
I also liked the grind of the Gateways.
I'll shoot them tomorrow and see if there is any difference, I doubt there will be.
As to the splicing...beyond my meager abilities right now, sorry!
But, I would think the Tru-Flights would be a better choice for splicing, they seem a little more "limber" or "soft"..maybe just my imagination, or the quill is a little thinner and softer on the Tru-Flights. The Tru-Flights seem a little more limber to fit into my bitzenberger clamp.
John