Replying to Buying new skis - head vs 4frnt

ok so there has probably been a thread similar to this, but i couldnt find it. anyway...

ok so right now i have some 4frnt STL's (two seasons old). in decent shape, but if i can get a good deal on some new skis, im gonna get 'em.

i like my 4frnts a lot, but i've really been liking the look of the Head skis last season, and the new ones coming out. and ive heard that head skis are bomb proof (im not huge into rails, im just learning them, i do boxes and jumps mainly). being from MN we have icy landings (for winter, you hear midwest, you think ice), which i'm not sure if it makes a difference for durability issues.

now as for head skis go correct me if i'm wrong, the mojo 90 is the backcountry ski? and the mojo 80 is the park ski? i like the grahpics on the 90 better then the 80, so how would the 90 fair in the park/midwest conditions?

also, how do head skis feel in comparison to the STL's. are they stiffer, softer..etc.

thanks.