I had a blue 400F back in 1976. It had a few quirks: the 6-speed gearbox, with its short pedal linkage, did not like to be shifted using the clutch, and preferred clutch-less upshifts with rev matching. The other was that, in the UK damp climate I was living in back then, it took a lot of cranking when cold before at least one cylinder would fire.
One day, after one starting failure, I opened the air box lid, and found the air filter partially submerged in water. After clearing the airbox drain and air drying the filter, all was great again. Aside from that, bike was enjoyable.
Roll forward to 2020, after 44 years, and I now have a 73 CB 350 four. I like it even more; at least its styling is more classic than the spartan 400F, and the passenger accommodations are a little better for a (small) passenger, since the foot pegs have their own mounts instead of moving with the swing arm.
Of course, at 66, I am no longer weighing 125 lbs; I am 50 lbs heavier now, and the 350F seems a little slower than the 400. But I like the 350F even more, as performance has never been my top priority, anyway.
In short, both great machines usable at any age and experience level.
