I have seen them launched both ways, rod and rail. I guess it comes down to how cool you are.
Do you want to impress the oldschool dudes with their silly launch lugs, 6 foot stainless steel launch rods and endless babble about multiple coats of toxic sanding sealer making their balsa look like glass; or do you want to be young, good looking, cool and hip, ripping your high powered bird off the rail flying the latest electronics. Are you scared to death of quarter inch rods inducing some sort of terminal rod whip on large rockets using more than an F motor, necessitating an all out ban on quarter inch rods? Are you stuck in the 20th Century with rods or have you made the great leap into the 21st Century with vastly superior rail technology? The thin walled Apogee kit is old school and I heard from one builder who started with the lug and later added buttons that adding the buttons was a pain given the need for reinforcement and aesthetic compromises. Maybe he will chime in on how he did it.
She is a big light kit that will act like a sail. Hey look! We have a little wind and the old fart can't launch because of his week rod and underpowered mellow motor designed for some sort of slow, smoky NASA style lift off. Bulletproof with light glass and use one of those awesome sparky motors that are banned out West. Launch off the rail, hear the applause from the crowd, put on your mirrored sunglasses and drive home in your Bugatti with your Trophy girlfriend in the passenger seat.