First off, let me say that my kids, age 6, 5, and 3 were so excited when they saw this thing come out of the box they practically rioted. In our house we have a saying, "so fun it causes crying", and the Nerf Vortex Pyragon with 40 disc drum magazine meets that standard and then some. Opening it up, the first thing I noticed was that the drum magazine looked like it might fit our old Nerf gun, the Vortex Praxis. Sure enough, the magazines are interchangeable. And for an awesome bonus, the Pryagon accepts the Praxis shoulder stock, too. See my photo. After giving the kids a turn and getting them out of the way I got to practice a little geek science on this baby. I dug out my professional chronograph (the Chrony Alpha) and was thrilled to find it could take readings from these toys. After 40 shots the stats are these: the Pyragon shoots the discs at an average feet-per-second of 50.6FPS, at the muzzle, with a standard deviation of 2.3FPS. Each disc weighs 39.1 grains, yielding a muzzle energy of 0.22 foot pounds. [sidenote: a modest pellet gun can shoot an 8 grain lead pellet at 530fps, yielding 5.0 foot pounds] I also tested our year-old Nerf Vortex Praxis: it produced only 43.7FPS with a standard deviation of 3.9FPS (0.17 foot pounds). Unless someone sends me a new one, though, I cannot say whether the poorer performance of the Praxis is innate to gun itself or due the wear and tear of a year's hard use. The Pyragon advertises slam fire, and I am happy to report it works just as well as advertised. I can shoot 10 rounds in a third as many seconds, putting every one on a six inch target at 10 feet. I'm sure hundreds of reviewers have written about the virtues of the new Nerf Vortex discs versus the old darts, so I will only say that after trying both with my kids I prefer the discs for distance, accuracy, marksmanship training, and rate-of-fire. But then again, the suction cups on the darts are super fun for shooting at windows. It's best to have both. I rated this "5 star" for educational value and I just want to explain that: it's because we use this toy to teach gun safety and handling. Our rule is never to shoot (or even point) the gun at anything other than a target. Violation of this rule means the gun gets put away for a day. I know they'll shoot at each other when they get older but I think it's never too soon to ingrain safe gun practices. Furthermore, the Vortex system is accurate enough that the guns can be used to teach basic marksmanship. We line up little toy soldiers on the floor, and pick them off. It's a great father-son (and father-daughter) activity. So there you go: it's more than fun, it's educational! P.S. for the geeks out there, here is my raw feet-per-second data... * AAAA BBBB CCCC DDDD EEEE FFFF GGGG HHHH 1 43.54 44.67 42.70 43.43 50.98 50.37 50.69 49.42 2 43.25 44.45 44.62 51.21 50.50 49.48 50.72 47.22 3 41.83 44.52 45.16 44.09 51.75 48.77 50.91 50.93 4 37.80 50.47 46.09 40.41 49.89 49.35 47.02 50.57 5 44.72 52.82 46.87 41.72 49.75 59.00 50.75 49.89 6 43.74 43.57 47.42 44.50 52.14 47.86 50.24 49.46 7 44.04 43.08 45.75 43.79 52.69 56.45 51.87 50.62 8 44.25 43.86 44.38 44.05 49.78 48.29 52.16 50.37 9 43.59 43.17 45.65 43.27 51.78 47.45 51.90 52.22 10 32.99 43.69 46.70 43.47 50.33 46.72 51.93 50.16 A: Praxis (old) with green disc (old) B: Praxis (old) with green disc (old) C: Praxis (old) with red disc (new) D: Praxis (old) with red disc (new) E: Pyragon (old) with green disc (old) F: Pyragon (old) with green disc (old) G: Pyragon (old) with red disc (new) H: Pyragon (old) with red disc (new)