Also received the 420 which I am enjoying. I've never used the 460 but have used some custom flat tails.
What really surprised me with the 420 is that I didn't feel any skidding on the short black fuse, coupled with the HPS880 so that's a big win

If you go black series and wing, go for the short otherwise it's quite twitchy. Someone mentioned that the upturned tips helps to go upwind too but I haven't looked at my angles closely yet to verify this.
With a kite I go back to the 390 stab however for better turning.