I can say the powerchokes especially the 7.3 is the best Ford diesel yet. I've driven both and can say I think the duramax is by far quieter, more powerful and when driven and tuned right a better engine. Both have loyal fan bases and they get about the same mpgs as well. But it comes down to what you like. Drive a duramax, you'll be impressed. I own a 7.3 and its got nothing on it. My friends duramax with 300,000 on it and the Allison trans (if no other reason than the Allison, buy it) has a programmable tuner on it and it pulls on the freeway like a vette. Just my 2c.
From where I sit with what's out in the driveway- the Ford in my signature and a 2002 Chevy 2500HD 4x4 ext cab shortbox Dmax/Allsion. The Chey will make 17-20 on the highway, pulls strong. Still pizzed over the injectors and the run-around at all the GM shops; finally has a trusted private shop do it for same price and same parts. Showing 150K so hope it runs out for a good while as its a nice pickup. The Ford, 1 injector (not a full set!), some glow plug work (needs the full smash, parts on workbench...) and the crappy TTB front. Pulls very good, maybe not as well as Chevy but there's a 75HP difference. Turns in 17-18 on hwy, can crowd 20 if I slow down to 55-60. Each has their place, at the Beck Ranch!
'94 1/2 F250 4x4, SuperCab XLT, 5 spd, SMF w/ Valaeo clutch, 4.10 (syn. lube), Cenex Maxtron 5W40 Syn, manual hubs, B&W Gooseneck hitch, Cooper ST Maxx tires in 235/85R16, authentic TYMAR intake, 4" AFE exhaust, FRP mod., SD starter, Isspro boost/pyro,digital thermometer, homebuilt exhaust brake, 188K Fresh factory injectors at 186K, TS-6 chip. "Its only a pickup. Trucks have a button on the shifter!"
It all comes down to personal choice. Drive what you like. My friends 01 Duramax has 300,000+ and never had any work done. I think there's a lemon in every bunch. The 6.0 fords from speaking to people are ok as long as you LEAVE THEM ALONE. When people start tweaking them is when issues arise. My 2cents