see, your standard inbred will take 4/5 inch forks, comes as geared or SS and is a nice bit of kit for the money. The 456, as the name suggests, takes a 4,5 or 6 inch fork, is avaliable as a geared bike only and is like a beefed up version of the inbred. I believe it can take 8inch rotors at the back, and if I remember correcrtly, all the tubes are the same diameter (generally bigger than the inbred). The inbred is more of a XC/ singletrack bike, where as the 456 is more of a “messing about in the woods bike”.
I replaced my Orange Patriot with a 456 as I wanted a hardtail that could handle a bit of DH and being thrown around, but could also be used for “normal” riding. If you’re keeping the MX comps on there, then go for the inbred and it’ll ride very nicely. If you’re thinking of putting some big forks on then go for the 456 and it to will be lovely, but in a very different way.