My experience is limited to commercial.
For our jobs, Code minimum work is rarely acceptable. The Contract specifies wire sizes beyond the Code, etc.
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Out in California, Title 24 supersedes the Code -- and it's growing like cancer.
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Ten years ago I had the displeasure to completely renovate a 1927 office tower downtown. My genius boss always stayed with copper and 2" EMT unless otherwise specified for feeders. (200A 3-phase)
This being his first (and only) high-rise it was news to him that copper feeders can only dangle so far until they reach support. Since the verticals had already been installed (and encased in concrete) the solution was Aluminum.
Fortunately his (4) feeder runs to the roof had been mis-calculated. He'd wildly over-sized the neutrals and wildly under-sized the bonding conductors. So the EMT was big enough to tolerate Aluminum.
When the bill came in he was $6,000 UNDER budget on the wire. (Remember what prices were?)
Overnight, he informed all of his foremen to upsize all underground feeders from now on: Aluminum to be used whenever the contract permitted.
(Albertson's accepts Aluminum feeders for all but motor circuits.)
This is but one example of how Code minimum thinking is ruinous.
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As for the residential practice of routing the most complexity into the overhead/fan boxes -- I'd hate to have to correct any circuit faults there!
In my world, I attempt to keep high junction boxes as simple as possible. I also favor generous gutters. The labor drain and high danger of working in packed gutters makes them losers. (I've seen guys knocked out by a sweet jolt of 277V -- the can was a nasty ball of connections -- and he had to brace himself against the strut rack to work it. Talk about well grounded, through the heart!)
