no, 6.0's are not the fragile POS that everybody online makes them out to be
get some tunes, get a monitor, watch EOT/ECT and drive the SOB
I would say "you couldn't pay me to drive a 7.3", but that's a lie... everything has a price
throttle response on a tuned 6.0 is unreal
the great thing about a 6.0 is it will rarely leave you stranded without lots and lots of warning...
injectors going bad? rough cold start, rough running until it warms up...
FICM going bad? really long/hard cold start (but it'll start!)
oil cooler clogging? EOT will start climbing
EGR cooler cracked? white smoke and antifreeze smell
head gasket blown? truck will puke under HEAVY load only at first
high pressure oil leak? truck won't start when hot
none of these things will leave you or your loving wife stranded... the only thing that will prevent limping it to a shop is not being able to start hot on a high pressure leak. But once the truck cools down, it'll start. Or, you can put a can of ether in the back and instruct her on how to use it in the case of an emergency.
7.3's are not 100% bulletproof/trouble free. They have fewer failure points, but you should set aside money for a good trans rebuild. I just can't deal with the lack of performance