The last 460 had about the same power as the 1st gen V10, however the Triton motors are quite a bit more reliable. While the 460 itself wasn't problematic, all the accessory stuff (fuel pump, cooling system, a/c etc) did not last near as long. The V10 as a total package will go much longer without any headaches to deal with. And the cooling system is more robust. I can haul 22,000 pounds up 10 mile long 12-15% grades in 100F heat, and not have to even turn down the dual A/Cs in my V10. The 460 will overheat pulling a 7% grade in 90F weather if you try to keep the A/C blasting.
Both respond well to breathing improvements, but only the V10 really gains power with new programming. Also, the V10 can easily go 500,000 miles even under severe commercial duty, while the 460 was pretty worn out by 200k under the same conditions. I'm at 386,000 with my V10.
BTW -I've had both. I picked up a 460-powered van for a while as a spare, and its still in the family.