If you can afford the diesel then get it. Yes it will cost more but the first time you tow something heavy it will be worth it. Vortec's are good engines but the dmax with the Allison is just awesome. As far as maintenance goes, all you will do is change the oil and put on a fuel filter once in a while. (Which you will do less often than a gas job). Aaaannnnnd, if you get the itch for more power (and you will) you can put a chip in it and have chingles of power and torque. My dad has a 2010 gmc with a chip and it will do smoke the tires on dry pavement.

IMHO with the little towing you will be doing the diesel engine "premium" is not worth it. Diesels cost more to maintain, that's a fact. I have one and I probably should have gotten a gasser  Good luck!

If you can afford the diesel then get it. Yes it will cost more but the first time you tow something heavy it will be worth it.

Yup that and bacon!
Seriously though I don't think I will buy another full size truck that is not a diesel, they just work.

I'd probably vote gasser. Cheaper, pretty damn reliable, gutless wonders.

That being said I have a diesel and love it. I got it for sole purpose of hauling crawler and old lady's horse trailer. The house trailer evolved from 2 horse bumper pull to a 4 horse, 20' gooseneck. My beater light weight 20' flatbed got canned and I have a 25' tandem dually that weights 6500# empty. I haul a lot of hay and whatever else i can as a side source of spending money now. If I had gotten a gasser to fulfill what I originally wanted a full size rig for, I wouldn't be happy with it anymore.

If you think you will never do anymore with truck than you are saying you will and you like to pinch pennies, get gas. But if there is a chance you will go bigger toy hauler/use it way more often in the future. Get a diesel.

I am also a GM guy but even owned a ford diesel for a short while before it exploded. I have done the same evaluation as you and have owned a 2001 6.0L gas 2500 pic:

it was even the 5 speed

and now my current truck, 2003 duramax/allison 3500 single rear wheel:


personally the 6.0/ 5 speed was a good truck when not towing and got ok fuel milage but after needing the crew cab for the kids and finding a good deal on the duramax i would not go back. the duramax has more power better MPG and will probably last longer. granted the oil changes and parts are more expensive, the towing charicteristics of the 6.0 just paled in comparison to the duramax so much it is worth the cost for me. granted i have a work truck so my duramax is only used for towing and hauling and does not get many miles (still at 115K for a 03) so i dont really use it for DD use but i have and even being a crew cab long bed i would drive it any day if i did not have my work truck.

if you are really tight on budget go 6.0 and it will get the job done but expect 8 MPG hauling the toyota or anything and 15ish empty. if you can afford it go with the duramax and get 15MPG towing up to 12kish and around 18-20 empty.  personally my truck had the injectors replaced under warranty when i bought it but has not had any problems since. I personally think most that have problems are the ones with tuners on them, stressing internals not designed for that type of power. If you stick with stock power (which i feel is plenty) and change the fuel filter with every oil change you should have a very reliable truck for many miles.

iirc oil changes on the 6.0 performed by me were around 40 bucks, oil change and fuel filter on the duramax will be around 100 bucks performed by yourself.  besides some tie rod ends and a u joint i ahve not done much else to my truck but i feel those to be regular wear items.

What year did they have to have the urea injection?

I'd think the diesels were better before that requirement.....

I like diesels but we run an '88 Chevy crew cab 1 ton.  454 with TBI gets the same 11-12 mpg weather its loaded, unloaded or towing a house.  So much more roomy inside compared to the '08 GMC and '06 crew cab we had.  Like driving around in your living room.  These can be had cheap and are flat out cool to drive around in. Handles and rides better than our newer trucks, period. They also take well to a cummins swap if you ever want more, but the big block is so cool.

They can be had cheap so no payments. We traded a well used quad for ours.

A new, modern diesel is of course better for almost every normal person, but my opinion is go old.  More bang for your buck and not a mommy wagon like all these newer trucks.