Pro Comp 4" vs Fabtech 4" Lift?

These Pro Comp/Fabtech 4" lifts look very interesting and similar - but one major difference seems to be the Pro Comp has a new crossmember, but no upper control arm - and the Fabtech has no crossmember, but it has upper control arms. Can anyone comment on the pro's/cons of these two lifts - or at least this theory of using a crossmember vs upper control arm, thanks.

Pro Comp 4":



Fabtech 4":

 

I had emailed fabtech about their lift and I was told it is closer to 3.5. So that is how they get away without a new crossmember. The rear is 1 inch only

I think procomp is a true 4 inches and about 2 inches in the rear. So it is a little taller all the way around. I would suspect if everything is properly dropped down then that is why no UCA's come with it.

Flip side no drop going 3.5" will need UCA to fix the angles as the whole thing doesn't drop. Not sure why fabtech uses new spindles with that sort of lift?

If 3.5 is good check into zone. They also have a 3.5 that is same as fabtech minus the spindles. Uses factory so you can had a more positive offset wheel