Where's the high nit screen on the T420/520?

Man I was really hoping to upgrade to one of these bad boys but I do a lot of work outside and need a high nit screen. Anyone know why they left it out or if it will be added later as an option? I do a lot of work outside (nothing crazy) and really like having the option for a brighter screen. Currently have the Dell e6400atg with the 720nit (or whatever it is) and it works awesome. Would love to have something similar.