Well, I'm aware of the website but most of the dealers shown there don't make any reference to the Mach series injectors making me think they're not selling them anymore. Also, most of the discussion involving Formula 1 injectors here on the TDR seems to have pretty much evaporated around 2011 or so. It's hard to say if that's because Don's not making 24 valve injectors anymore, or if people are just selling their 2nd gen trucks.
All the 24 valve injector discussion I've seen over the past two years mainly mentions DDP. The DDP injectors look interesting, but I've been so happy with my Mach 1s that I was looking to stick with the Mach series.