I will tell you this-
Yes, the kit was pricey.... However, no. 1, did pick up some mpg. I saw a one to two per gal. No. 2, did replace the already-dry non greasable crappy axle joints with end greasable joints that i am sure will last the life of the vehicle. No. 3, the hub bearings are very HD and are servicable, although i seriously doubt they will ever need any attention. No. 4, I can tell if after having locked the hubs in for a 'needy' situation, that once i have hit the road, the steering wheel is heavier and the vehicle is noisier...until unlocked- draw from that what you will. And no. 5, already mentioned the more substantial rotors and related braking improvements.
Just my experiences.