Well, I think Honda simply did a stellar job with this particular engine (750), myself. I rode for 14 years in all weather, heavy traffic, etc., with Vetter fairing AND lowers enclosing the engine. I even toured the desert southwest in August that way with my brother on his 500 (similarly equipped), and his overheated and died in Phoenix 110+ degree traffic, mine just got hard to shift. Never another whimper or complaint, until ethanol-enhanced fuels came along: now it boils in the carbs if I do this, so I ride lowers only in cool weather.
I have seen this engine with 1000cc kits added, with the fins resleeved so big that only 1/4" of fin was left: no problems. I have seen the oil temps on my own 750 hit 260 degrees: no complaints (20w50 Castrol oil). In last summer's teardown (at 112,000 miles on the bottom end), I mic'ed the crank and it showed only 0.0008" wear in all of that, which included a lot of abuse at 14000 RPM when I raced it: still this same crank. The bearing clearance on the mains is 0.0018", on the rods the worst one is 0.0021". Stock is 0.0008"-0.0012", wear limit 0.0032".
The only effects I have seen from hot, slow traffic is wear on the center 2 cam bearings. Honda jetted the upper oil passages to force oil to the crank before the top end, which results in oil starvation in the center 2 cam bearings in heavy, hot traffic. This often shows up as false "cam chain noise", which is really cam flex, making the cam chain flutter at low engine speeds. Typically, these bearings have more than 0.008" clearance after only 30,000 miles. Mine are at 0.012" now.
All that said, there is one thing you must never do with any of these I-4 engines: heavy throttle openings in higher gears at low engine speeds in hot, heavy traffic. This WILL put metal-to-metal together in the crankshaft, at the rods, top side bearing. So, for my two cents' worth, stick with some more RPM. I use the 15 MPH rule, myself: out of 1st at 15, out of 2nd at 30, out of 3rd at 45 as a minimum.
