I agree with what Dirtleg has said.
Keep up on the basic maintenance and it will give you a long service life. I change the oil and filter every 5k miles with Motorcraft Oil and Filters. I change the fuel filters every 10k miles with Motocraft filters. I get the oil and filters at Advance and a full service is about $100. I would STRONGLY recommend not using anything but the Motorcraft filters. There have been many 6.0 damaged by aftermarket Oil and Fuel filters. The oil filter coming apart and sending filter innards throught the engine and HPOP system. Some aftermarket Fuel Filters do not have the water block membrane on them... and this as runined may injectors, and at one time, if Ford found any fuel filter installed that was not a Motorcraft, especially if it did not have the membrane, the would not warrenty the damaged injectors, or the repair costs associated with them. I feel very strongly to NOT put a tuner/chip/programmer of any kind on a 6.0. I know many have had very good luck with a tuner, but, I have found that in stock form... and yes mine is 100% stock from the stock air intake to the factory Cat and exhaust. The only "mod" that I have done is to install a FUMOTO valve in the oil pan. It will do anything that I ask of it, get pretty good milage and will start and take me and my family anywhere I want to go any time I turn the key. Travis (argve) has driven my truck, and he has even said he sees no reason to turn up my truck.... and that says alot. These are already running at 325hp/560Tq right out of the box. An IDI with a turbo gets just over 200 and a stock 7.3PSD was anywhere from 190-290 in the last model years, so going from a turbo IDI to a stock 6.0 is a world of difference from the start.
I have not had any cold start problems with my truck after I had the computer flashed with the Inductive Heating flash. I have started it below freezing without it being plugged in. I try to plug it in, just so that it is easier on the engine, and I have heat quicker.
From what I have found with mine, is do the recommened maintenance every 5 or 10k miles, and put fuel in it and it will treat you right.
Also, it should have the ESOF 4x4 system..... the front hubs are a vacuume actuated / manual lockout combo. When you turn the switch to 4x4, it will automatically lock the front hubs in. There is also a "knob" on the lockout that allows you to lock in the hubs all the time. I recommend that you, once a month or so, to manually enagage and disengage the lockouts, this keep them free and moving...... this is over and above just running the 4x4 peoiodically to keep everything lubed in the t-case and front axle.
I think you will really like this truck and if you have any questons please ask......