Honestly, for what most drivers use their cars for these days, I can't see a practical use for either the G-Max or the Alterkation, IMO. Sure they are lighter weight, provide additional engine clearence and are highly adjustable, but very few classic owners ever use their cars at a venue that requires the type and range of adjustability that comes with these types of suspension systems. For those that do participate in any sort of organized vintage racing the rules typically prohibit such radical mods as these unless you are running in an all out, full bore class, in which case the purpose built cars will likely hand you your butt.
It seems a lot of guys are willing to throw buckets of money at an entirely new system when all the really need is to update the old spring rates, change their alignment, and buy for some really, really good shocks. Then again, there certainly is a growing segment of the market who wants all the go fast, look cool goodies for the parking lot derbies too. I don't suppose they are any less a hot rodder.