The newer 462s have more snort than the earlier ones, it's measurable, they pull a 28" bar much better.
400s run good, but still have a baby oiler and an AV system that isn't designed to carry a long bar for people who are actually gonna work the saw daily. It's a 20" bar saw, if you have a built in vagitometer you may notice the weight difference between a 462 and 400, I don't know where you personally stand with that.
In stock or ported form I'd take the 462, especially with the updates the 462 has had.