I like the modern Buck because it functions better.
When Buck took over making the 300 series, they redesigned the knives.
♦ The sheepsfoot got moved to the side away from the main blade That makes it easier for me to open the sheepsfoot. Makes the spey a bit more awkward to get to, but I use a sheepsfoot a LOT more than I use a spey.
♦ The three spring design means they didn't have to crink the sheepsfoot. So when you open it, it comes straight out instead of coming out at an angle. That makes it more controllable and easier to cut a straight line, which is what I mostly want to do with a sheepsfoot blade.
♦ The 420HC is hardened to a higher hardness than the Camillus, so the modern Buck actually holds an edge better.
♦ The "edge 2000" extreme hollow grind profile works better for what I do with a knife. It doesn't work well for peeling apples, but works great for pretty much everything else.
For a working knife, the modern Buck is just a better design, even if the Camillus Buck is a bit more elegant.