Well while the UltraSabers don't really have "power up/power down" I have noticed that it does tend to... I dunno how to say it...
When you ignite the saber, yes it's "instantaneous" but you can still sorta see the light go up the blade, and down the blade.. So it's SORTA there... but it's just faster. To be honest. I like it more than the Master Replica blade's power up/down style. It seems more realistic since.. well.. light travels very quickly..
But I undertand where you're coming from. I think I want to do the same but. Yeah. Money. I'll wait for a while heh.