Brett replied:

In my opinion you gain nothing other than the spedy spare parts availalilty when Toyota service a vehicle out of warranty. What you pay for a service from toyota for your 80 series I used to pay to have my 350 hp 14 litre Cummins powered International ,with a 40 ltr sump, serviced and I would get some change too.

I have done most oil changes myself and have even gone to Ultratune workshops and given them the oil I want put into the vehicle..and waited for them to do it. Most repairs to my vehicle have been done by a truck mechanical workshop.

Repairs. I have had brakes and a diff repaired by dealers in the Repco chain of franchises and have had to claim a warranty once which was dealt with without fuss. If you are not going to travel for months at a time I would be trying to Identify a good local repairer. The 4x4 joints can be a bit pricey. I prefer to take my vehicle to a heavy vehile truck repairer as for them it is "light work" for a change , they are used to repairing stuff and just don't remove and replace, and in general they are probably a better class of mechanic.
If you are travelling and you want some sort of standardisation go to a Repco, Ultra Tune or some sort of National type dealer arrangement.