The old Okie 5-2 and the 3-4 are essentially the same. The major difference is whether or not your outside guys are in two-point - standing up or down in 3 or 4 point stances. Coaches always used to teach linemen/pass rushers to get down in the 3 or 4 point. I think the evolution of the way they call (or don't call) holding as well as cut blocks has made the down way less advantageous, and the two point makes sprinting around the corner easier. The 2-4-5 is basically a 4-2-5 with stand up pass rushers.

Not to turn this into another pro or con thread about Capers, but I much prefer all the creative pass rushing and run blitzes over the old plain vanilla way.